Mind, Brain and Adaptation in the Nineteenth Century: Cerebral Localization and Its Biological Context from Gall to Ferrier
by
Robert M. Young
[ Contents | Preface | Introduction | Chapter: | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | Bibliography ]
I GALL AND PHRENOLOGY:SPECULATION versus OBSERVATION versus EXPERIMENT
phrenology: n. a doctrine that the excellence of mental faculties or traits is determined by the size of the brain area upon which they depend and that this can be judged by the development of the skull overlying the area. Modern psychology rejects entirely the faculty psychology; and modern neurology has entirely disproved the kind of brain localization asserted in phrenology. The practice today is a form of quackery.H. B. and A. C. English, 1958.Phrenology has been psychology's great faux pas.J. C. Flugel, 1951.No one can refuse them the merit of patient enquiry, careful observation, and unprejudiced reflection. They have performed the useful service of rescuing us from the trammels of doctrines and authorities, and directing our attention to nature; her instructions cannot deceive us. Whether the views of Gall and Spurzheim may be verified or not, our labours in this direction must be productive, must bring with them collateral advantages. Hence they may be compared to the old man in the fable, who assured his sons, on his death-bed, that a treasure was hidden in his vineyard. They began immediately to dig over the whole ground in search of it; and found, indeed, no treasure; but the loosening of the soil, the destruction of the weeds, the admission of light and air, were so beneficial to the vines, that the quality and excellence of the ensuing crop were unprecedented.William Lawrence, 1822.SOME distortion is inevitably involved in beginning an historical study at a point in time. In this instance the problem is increased by the fact that the starting point could be seen not only as arbitrary but also as absurd. Franz Joseph Gall (1758-1828) was, after all, the founder of what was later known as phrenology: the belief that important traits of character can be determined from a study of the bumps on the skull. Phrenology, of course, is nonsense; it has received no serious attention from the scientific community in the present century. To read about it in a book that is readily available today one must look in Gardner's Fads and Fallacies in the Name of Science, where it shares a chapter with the10pseudo-sciences of physiognomy, palmistry, and graphology.[1] Even in the 1840's phrenology was in such bad repute that Professor Adam Sedgwick felt that he could best indicate his low opinion of Robert Chambers' Vestiges by stressing its links with 'phrenology (that sinkhole of human folly and prating coxcombry).[2] It would seem, therefore, that some explanation is required for beginning a study in the history of science that is concerned with the functions of the brain, with the works of Gall.Cerebral localization may be defined as the doctrine that various parts of the brain have relatively distinct mental, behavioural, and/or physiological functions. Speculative localization of functions, based on the belief that the brain is the organ of the mind, is as old as Herophilus and Galen, that is, as old as anatomy and physiology themselves. In the fourth century A. D., Nemesius localized specific faculties in different parts of the brain, and this approach was the dominant characteristic of medieval analyses of the relations of brain to mind. However, these localizations had three features which fail to recommend them to us. They were ventricular; they were speculative; they were based on a faculty psychology. Medieval ventricular localization was allied with a pneumatic physiology which does not here concern us. Its faculties were derived from the Platonic division of the mind into sense and intellect or from the tripartite Platonic soul of passion, spirit, and reason. These divisions were increased until seven to nine faculties were usually mentioned: sensory perception, intellect, memory, and imagination were the faculties most often mentioned, while attention, language, judgement, will, and movement also appeared in various classifications. The usual localizations were sensation and imagination in the anterior ventricles, reason or thought in the middle, and memory in the posterior. Vesalius began the attack on these notions by protesting against those philosophers who 'fabricate, like a Prometheus, out of their own dreams . . . some image of the brain, while they refuse to see that structure which the Maker of Nature has wrought.[3] Nevertheless, after men had begun to look directly at brains, and after the emphasis had been shifted from the ventricles to the solid portions of the brain, these same faculties were still speculatively localized in various cerebral structures. The issue of faculty psychologies will concern us as we look at Gall's views.1 Gardner, 1957, pp. 292-8.2 Quoted in Gillispie, new ed., 1959, p. 165.3 Singer, 1952, p. 4. On the early history of localization, see Soury, 1899; Macalister, 1885; Pagel, 1958; Woollam, 1958; Magoun, 1958; Clarke, 1962.11The position just before Gall began his investigations can be gathered from the view held by Prochaska. He published a Dissertation on the Functions of the Nervous System, in 1784 at Vienna, twelve years before Gall took his medical degree there. He pointed out that the theory of cerebral localization, though probably valid, had as yet no scientific basis.But since the brain, as well as the cerebellum, is composed of many parts, variously figured, it is probable, that nature, which never works in vain, has destined those parts to various uses, so that the various faculties of the mind seem to require different portions of the cerebrum and cerebellum for their production.[1]The 'divisions of the intellect', each of which 'has its allotted organ in the brain' are given by him as' understanding, . . . the will, and imagination, and memory.[2] However, Prochaska qualifies his analysis by saying.Hitherto it has not been possible to determine what portion of the cerebrum or cerebellum are specially subservient to this or that faculty of the mind. The conjectures by which eminent men have attempted to determine these are extremely improbable, and that department of physiology is as obscure now as ever it was.[3]In 1799, Xavier Bichat, the eminent anatomist whose tissue theory transformed histology, could still maintain confidently that the brain was the seat of the intellect but was not the seat of the passions.[4] This was the state of affairs around the time when Gall began his investigations.Gall's work is the proper beginning point because his was the first empirical approach both to the nature of the faculties and to their localizations. Gall's work will be considered here in terms of four separate issues: What are the functions of the brain? How are they localized in the brain? How can one determine the functions and their localizations? Finally, Gall's method will be contrasted with that of experiment. What are the Functions of the Brain?Gall's detailed analyses of the functions of the brain and their localizations have been totally abandoned by subsequent investigators1 Prochaska, translated Laycock, 1851, p. 446.2 Ibid, p. 447.3 Ibid., p. 446.4 Bichat, no date, pp. 62-3, 252.12except for some very lucky guesses. However, it is still the case that his great contribution to psychology and to the understanding of the nervous system was the thesis that behaviour and the functions of the brain, as well as its functional organization, are amenable to objective observation. Before Gall, psychology was a branch of the philosophic discipline of epistemology, and divisions of the brain into functional regions had never been empirically related to behaviour. Gall combined a principle of analysis into behavioural and anatomical units with a requirement that we actually look to external nature rather than rely on introspection alone for our classifications of mental and behavioural phenomena.Gall reports that the object of all his researches is 'to found a doctrine on the functions of the brain. The result of this doctrine ought to be the development of a perfect knowledge of human nature.[1] He bases his psychophysiological system on the following suppositions:1 That moral and intellectual faculties are innate.2. That their exercise or manifestation depends on organization3. That the brain is the organ of all the propensities, sentiments, and faculties.4. That the brain is composed of as many particular organs as there are propensities, sentiments, and faculties, which differ essentially from each other.[2]As a methodological corollary to these suppositions, Gall makes a fifth assumption:And as the organs and their localities can be determined by observation only, it is also necessary that the form of the head or cranium should represent, in most cases, the form of the brain, and should suggest various means to ascertain the fundamental qualities and faculties, and the seat of their organs.[3]As his cranioscopy or theory of bumps was accepted more and more uncritically by him and his followers, it guaranteed the brevity of attention which scientists paid to his detailed findings. It was the undoing of his psychological and physiological work.The beginnings of Gall's psycho-physiology arose from childhood observations made on his playmates. He notes that each of them had ‘some peculiarity, talent, propensity, or faculty, which distinguished1 Gall, translated Lewis 1835, 1, 55.2 Ibid., I.3 Ibid., I.13him from the others'. In particular, he notes that those who learn by heart with great facility have 'large prominent eyes'.[l] He discovered this same correlation in schoolmates and later on fellow-students at university. These chance observations might provide any thoughtful observer with enough material for a conjecture, which he might formulate as a hypothesis and set out to test. It will become apparent that Gall's method encouraged him to formulate the hypothesis but failed to provide the means for testing it. He could find supporting observations, but he could not falsify it.Gall makes the induction:I could not believe, that the union of the two circumstances which had struck me on these different occasions, was solely the result of accident. Having still more assured myself of this, I began to suspect that there must exist a connection between this conformation of the eyes, and the facility of learning by heart.[2]Having made the induction, he generalizes it:Proceeding from reflection to reflection, and from observation to observation, it occurred to me that, if memory were made evident by external signs, it might be so likewise with other talents or intellectual faculties. From this time all the individuals who were distinguished by any quality or faculty, became the object of my special attention, and of systematic study as to the form of the head.[3]It should be noted that Gall has so far been doing straightforward physiognomy.The step in his reasoning which changes our view of Gall from being the founder of an empirical psychology based on physiognomy (which, as I shall try to show, is very interesting in its own right) to being the founder of a very advanced functional psychology and the modern concept of cerebral localization, is the following:I had in the interval commenced the study of medicine. We had much said to us about the functions of the muscles, the viscera, etc., but nothing respecting the functions of the brain and its various parts. I recalled my early observations, and immediately suspected, what I was not long in reducing to certainty, that the difference in the form of heads is occasioned by the difference in the form of the brains.[4]1 Gall, 1835, I, 57-8. 2 Ibid., I, 58-9. 3 Ibid., I, 59.4 Ibid., I.14Given these two sorts of data-external signs and marked propensities or talents- Gall believed that he had a method for discovering the functions of the brain and their local organs in the nervous system. He also arrived at the novel, and historically very significant, convictions that the functions had to be discovered and that this was a task for the naturalist, not the philosopher. In order to maintain this conviction, though, he had to find an answer to the prevailing belief among the followers of Locke and Condillac that all faculties, propensities, and talents are derived from experience: the sensationalist hypothesis that men are born equal and become different through education and accidental circumstances.We have now raised two issues: the belief in external signs of character, and the problem of the sources of the faculties, propensities, and talents, In order to appreciate Gall’s position on these matters, it is necessary to examine his views in the light of two traditions: physiognomy and the sensationalist psychology deriving from Locke.Duncan, King of Scotland, assures us that ‘There’s no art/To find the mind's construction in the face.[l] Gall would have agreed,[2] but since the time of Aristotle, attempts have been made to infer character (and to achieve insights about the macrocosm) by studying the external signs of bodies.[3] The specific claims of contemporary physiognomist were absurd, but there is something to be learned from the aims of their pseudo-science: the attempt to find stable and reliable phenomena in the objective world of matter and motion which indicate mental or emotional phenomena which cannot be observed directly. It is as an alternative to introspection that physiognomy recommends itself. Gall rejected as useless the holistic and vague assertions of Lavater that all parts of the body reflect all others to one who is observant enough to see, but he did grasp the significance of Lavater’s belief that all truths are ‘truths of the surface’. Lavater could only correlate external signs with characterological observations and believe that he had reliable guides. Gall felt that he could demonstrate the dependence of his external signs on the size of the underlying portions of the cerebral hemispheres. In the event, Gall too was wrong, but his hyphothesis was extremely plausible at the beginning of the last century, and it played a very important part in the transition from speculations about.1 Shakespeare, Macbeth, I. iv. 11-12.2 Gall, 1835, V, 261 ff.; Ibid., 1, 17-18. 3 See Thorndike, 1958; VIII, 448-75; Macalister, 1885, XIX, 3-5; Allport, 1937, pp. 65-78; Lavater, translated Holcroft, 1804.15unspecifiable physiological homogeneity to the experimental study of the brain.The second tradition in the light of which Gall's work should be viewed is the sensationalist psychology derived from Locke. Locke had set out to explore the nature of the human understanding by considering 'the discerning faculties of a man, as they are employed about the objects which they have to do with'.[1] The tradition which derived from Locke's work gave rise to an intellectualist psychology about the limits of understanding, the sources of ideas and the relations between minds and objects in the processes of learning and knowing. The categories and operations which Locke defined and studied were therefore intellectual ones. His first task was to free philosophy from the tyranny of Platonic and Cartesian special sources of knowledge-the innate ideas. It was in reaction to this rationalist extreme and in the name of empiricism that Locke put forth a tabula rasa view of the origin of the contents of the understanding. Locke's views reached Gall in the more extreme form of Condillac's sensationalism. Condillac rejected the second of Locke's sources of ideas, reflection. He sought to derive all the faculties and even instincts from simple sensations, and the principle of seeking pleasure and avoiding pain. Condillac's method was typical of the sensationalists: he spoke in the name of empiricism while he conducted his arguments by means of elaborate speculations about the successive addition of the senses to a statue.[2] Condillac's method of analysis and sensationalist convictions were represented by the movement called 'Idéologie', whose influence prevailed in Paris when Gall reached there in 1807.[3]It was therefore natural for Gall to express his own theories in relation to the conceptions of Locke, Condillac, and their contemporary disciplines, Cabanis and Destutt de Tracy. He rejected the tenets of sensationalism and sought to replace their epistemological psychology with a biological one. He replaced the tabula rasa view of the mind with a theory postulating a set of innate, inherited instincts transmitted in the form of cerebral organs, whose activity varied with the size of the respective organs. He argued that the senses were the instruments of these instincts instead of their source.In rejecting the tabula rasa view, Gall was not rejecting empiricism. In fact, he argued that it was the sensationalists who had failed to be1 Locke, 5th ed., 1961, 1, 5.2 Condillac, translated Carr, 1930.3 See Cabanis, 2nd ed., 1805; Rosen, 1946; Boas, new ed., 1964; Temkin, 1946 and 1947; Vartanian, 1960.16empirical enough. They had failed to observe nature and to note the extreme variations among men and among different species of animals, differences which could not be accounted for in terms of their immediate environments and experiences alone. There was something 'biologically given' in the abilities of men and animals, and it was this that Gall maintained in the face of the sensationalism of his time. He was not upholding the doctrine of innate ideas; he was upholding differences in natural endowment. This viewpoint led him to reject the optimism of the more sanguine environmentalists and to insist that the moral perfectibility of the human species is confined within the limits of its organization.[1] He held this same view with respect to different species and to different individuals within a given species. The ethical and forensic implications of this position gave Gall much trouble within his own thought, and their recognition by critics had led to the proscription of his lectures in Vienna and to constant charges of materialism and fatalism, which he answered feebly as seen from our vantage point.[2] However, these issues in his thought cannot be treated here. The important point is that Gall's concept of innateness served biology, not revelation or a Socratic doctrine of reminiscence.Gall attempted to replace the speculatively derived, normative, intellectual categories of the sensationalists with observationally determined faculties which reflected the activities, talents and adaptations of individual organisms and were the determinate variables in individual behaviour. In setting out to search for such categories, Gall insisted on the unity of man with the rest of nature, and applied the methods of the naturalist to man more thoroughly than had been done before. His aim was that psychology should cease to be the domain of the speculative philosopher and should become the special study of the naturalist and physiologists.[3] That is, Gall saw the study of the functions of the brain-what is now called psychology-as a biological science. There is no simple dichotomy between a representational psychology and an adaptational one-between the epistemological and biological views of the goals of psychology. Locke and Gall both speak in terms of adaptation. But when Locke does so, he is concerned with the adaptation of the understanding to its proper objects for knowledge;1 This view extends to man's appreciation of the Deity: the pervasive religious ideas of man and revealed religion would have been absolutely impossible if the human species had not been endowed with the appropriate nervous apparatus for having these experiences. Call, 1810-19, IV, 256.2 See Gall et al., translated Combe, 1838; Temkin, 1947; Lange, 3rd ed., 1925.3 Gall, 1835, 1, 62.17the operations of the understanding are performed for the sake of reaching true inductions. He assures us that God has given men 'whatsoever is necessary for the conveniences of life and information of virtue; and has put within the reach of their discovery, the comfortable provision for this life and the way that leads to a better'.[l] Our senses, faculties and organs are fitted to the conveniences and exigencies of this life and our environments.[2] Locke's analysis is not concerned with what these environments require and how the faculties are specifically adapted to them; it is concerned with the instrument for knowing objects-the understanding. Gall's position on this issue is in some respects a striking anticipation of the adaptational or functional view of psychology which was developed half a century later in the wake of the theory of evolution. The functional viewpoint which Gall shares with later workers also inevitably concerns itself with the adaptation of the mind to its proper objects, but in a wider context; the role of mind in the interactions of a behaving (not primarily a knowing) organism with its environment. The basic issue is not the content of psychological experience but the activities of the man or animal which do or do not promote survival or mastery over the physical and social environments. However, Gall's psychology is pre-evolutionary. In stressing its functional, biological form and contrasting this with the older elementist, epistemological psychology of the Lockean tradition, it is necessary to keep this important historical limitation in mind.While Gall differs profoundly from previous psychologists on the point of what adaptations are for, he is nearer Locke than the post-Darwinian psychologists on the question of how adaptations occur. He did not believe that they evolve through the dynamic interaction of organisms with their respective environments by means of natural selection. Rather they are set for all time by the place of an organism in the 'great chain of being'.[3] This static view of nature was the major generalization in biology until it was replaced by the theory of evolution. It dominates the details of Gall's psychology, making his faculties isolated and independent and leading to a relatively uninteresting character typology that almost completely fails to fulfil the promise of his most exciting conception of the domain of psychology.The grounds for Gall's rejection of the old faculties were that they were neither determinate for individual and species differences, nor1 Locke, 1961, I, 7.2 Ibid., 1, 250-3.3 The classical discussion of this concept is Lovejoy, new ed., 1960.18empirically derived. His rejection of faculties which are normative, or concerned with mind in general, in favour of those primitive characteristics of human nature which might explain individual differences, is the basis for his recognition as the first modern empirical psychologist of character and personality.[1]Gall reviews the categories of psychological analysis that had been put forward by various philosophers and physiologists, with special emphasis on those of the sensationalists.[2] His conception of the domain of psychology makes their categories quite useless. Gall's faculties are designed to serve a purpose quite different from those of the philosophers. He sees the goal of psychology as a differential one with its domain as the behaviour, roles, talents and differences of men and animals. Since the normative psychology which he opposed was preoccupied with mind in general and the relations between the mind and potential objects for knowledge, Gall argues,Whether we admit, one, two, three, four, five, six, or seven faculties of the soul, we shall see, in the sequel, that the error is always essentially the same, since all these faculties are mere abstractions. None of the faculties mentioned, describes either an instinct, a propensity, a talent, nor any other determinate faculty, moral or intellectual. How are we to explain, by sensation in general, by attention, by comparison, by reasoning, by desire, by preference, and by freedom, the origin and exercise of the principle of propagation; that of the love of offspring, of the instinct of attachment? How explain, by all these generalities, the talents for music, for mechanics, for a sense of the relations of space, for painting, poetry, etc?[3]Gall does not deny the existence of the philosophers' categories. They have meaning but only as abstractions and generalities:they are not applicable to the detailed study of a species, or an individual. Every man, except an idiot, enjoys all these faculties. Yet all men have not the same intellectual or moral character. We need faculties, the different distribution of which shall determine the different species of animals, and their different proportions of which explain the difference in individuals. All bodies have weight, all have extension, all are impenetrable in a philosophical sense; but all bodies are not gold or copper, such a plant, or such an animal. Of what use to a naturalist the abstract and general notions of weight, extent, impenetrability? By confining ourselves to these abstractions, we should always remain in ignorance of all branches of physics, and natural history. This is precisely what has happened to the philosophers with their generalities. From most ancient to the most modern, they have not made a step further, one than another, in the exact knowledge of the true nature of man, of his1 See Bain, 1861 ; Lewes, 2nd ed., 1857 and 3rd ed., 1871 ; Allport, 1937; Spoerl, 1935-6.2 Gall, 1835,1, 80-83.3 Ibid., I, 84.19inclinations and talents, of the source and motive of his determinations.[1] [Emphasis added].With the judgement that 'The most sublime intelligence will never be able to find in a closet, what exists only in the vast field of nature,[2] Gall turns his attention away from speculations and toward common society, family life, schools, the jails and asylums, medical cases, the press, men of genius, and the biographies of great or notorious men. Gathering together the variations among the individuals he has observed, and adding to these the results of his comparative studies of animals, he concludes that they cannot be explained in terms of the faculties of the philosophers. In general, he maintains that 'every hypothesis, which renders no reason for the daily phenomena which the state of health and the state of disease offer us, is necessarily false'.[3] It is this requirement, to explain individual differences, that leads Gall to insist both on the innateness[4] and the plurality of the faculties and their organs.[5]Having rejected the normative faculties of the philosophers, Gall was required to supply an alternative interpretation of the significant factors in mental life. It has already been mentioned that he viewed the brain and its functions in terms of an analogy with other bodily organs and their functions, and that his movement from mere correlation of external signs with striking behaviours to his emphasis on the brain was the most significant step in his reasoning.[6] Gall's second, third, and fourth basic suppositions were intimately concerned with the consideration of mind, behaviour, and character as functions of the brain. There are three stages in Gall's thought on the issue: his analogy of organ and function, the relations between this analogy and the traditional mind-body problem, and his reversion to a faculty psychology.Gall juxtaposes his physiognomical discoveries with the prevailing ignorance of the functions of the brain and its various parts. He uses the analogy with other organs and their functions repeatedly in his arguments to establish that the brain is the organ of the mind. For example, in arguing against the view that every other function has a particular apparatus of its own-seeing, hearing, salivating, producing bile-he asks of Nature, 'But, if she has constructed a particular apparatus for each function, why should she have made an exception of the brain? Why should she not have destined this part, so curiously contrived, for particular functions?’[7]1 Gall, 1835, I, 88-92 Ibid., V, 317.3 Ibid., V, 251.4 Ibid., I, 137.5 Ibid., II, 268.6 See above, p. 13.7 Gall, 1835; II, 99-100.20His approach to the traditional mind-body problem is to argue that the soul or mind is not a principle, acting purely by itself, which produces the faculties and propensities. Rather, 'The faculties and propensities of man have their seat in the brain'.[1] The whole of the second volume of The Function of the Brain is concerned with showing that the faculties and propensities depend on organization and that the organization involved is the brain. This was not a new view. It is said to have been held by the author of the first work which mentions the brain, the Edwin Smith Papyrus.[2] It was held by Hippocrates, who identified the brain as the cause of all of the operations of the understanding.[3] In defending himself against the charge of materialism that led to the proscription of his lectures in Vienna, Gall argues forcefully, and in detail, for the antiquity and repeated appearance of the belief that the brain is the organ of the mind.[4] Cabanis had even used the specific 'functional' argument:In order to form for one's self a just notion of the operations which result in the production of thought, it is necessary to conceive of the brain as a peculiar organ, specially designed for the production thereof, just as the stomach is designed to effect digestion, the liver to filter the bile, the parotids and the maxillary and sublingual glands to prepare the salivary juices.[5]However, no one before Gall argued for the dependence of the mind on the brain in such detail, specifically disproving the role of other organs, specifically including all the intellectual and moral propensities, and demonstrating countless instances of the parallelism between variations in the brain and variations in mental and behavioural phenomena. He showed all this by means of comparative studies on animals, the development of children, ageing, and diseases of the brain. Gall demonstrated again and again that the functions varied as the brain varied. It was Flourens, no friend of Gall's psychophysiology, who acknowledged thatthe proposition that the brain is the exclusive seat of the soul is not a new proposition, and hence does not originate with Gall. It belonged to science before it appeared in his Doctrine. The merit of Gall, and it is by no means a slender merit, consists in having understood better than any of his predecessors the whole of its importance, and in having devoted himself to its1 Gall, 1835, I, 10.2 Castiglioni, 2nd ed., translated Krumbhaar, 1947, p. 57. 3 Hippocrates, translated Adams, 1949, p. 138. 4 Gall, 1838, pp. 315-21. 5 Cabanis, 1805, I, 152-3.21demonstration. It existed in science before Gall appeared-it may be said to reign there ever since his appearance.[l]Having established this conclusion, Gall sets out to Systematically exploit it. The whole of the third volume of his Functions of the Brain is devoted to the proof of the plurality of the functions of the brain and the plurality of their 'organs'. Again, he argues by analogy with other organs. If each of the senses has its own specific material basis, then each of the functions of the brain has its own organ. The analogy of mental and behavioural phenomena as functions of a structure or organ could not be fully appreciated until it had been firmly established that the brain is the organ of the mind. When one does begin to exploit the analogy of the brain with other organs, one is led naturally to consider what role it plays in the economy of the organism and its interactions with the environment. Here are the beginnings of a functional psychology, and one can see that this approach naturally led Gall to a concern for the phenomena of everyday life, character, talents, and roles in society. The change of emphasis from a psychology of the soul as an insulated substance, which performs intellectual operations in relation to objects for knowledge, also becomes clear and natural. Locke's epistemological analysis and the faculty psychologies of Reid and Stewart are concerned with the operations, faculties, and powers of mind as an autonomous substance, while Gall concentrates on the mind as a function and considers its functional role.[2]Gall's understanding of the explanatory goals of psychology was immensely enriched by his concept of mental activity and behaviour as functions of the brain. Yet, having proposed the concept of function as an alternative to the old faculty view, he retreats into the latter in his detailed psychology. To be sure, his faculties are of a new kind, given their functional framework, but they are faculties none the less, and his detailed psychology suffers from all the defects of the faculty view.The circularity of faculty psychologies has been recognized since1 Flourens, translated Meigs, 1846, pp. 27-82 George H. Lewes was impressed by Gall’s biological point of view and observational method. Lewes' chapter on Gall in his History of Philosophy, gives an excellent and balanced view of the value of Gall's approach and principles, while rejecting Gall’s detailed attempts at psychological explanation. On the issue of functional thinking, Lewes says, ‘He first brought into requisite prominence the principle of the necessary relation, in mental as in vital phenomena, between organ and function. Others had proclaimed the principle incidentally, he made it paramount by constant illustration, by showing it in detail by teaching that every variation in the organ must necessarily bring about a corresponding variation in the function’. (Lewes, 3rd ed., 1871, II, 416).22Galen,[1] and the point was reiterated by Descartes, Locke, and Flourens before Herbart's criticism sounded its death knell. The form of explanation used by medieval psychologists, by Wolff, Reid, and Stewart, and by the phrenologists has been uniformly criticized by late nineteenth and twentieth century psychologists for confusing classification with explanation. Faculties are only class concepts invested with ' a fictional reality. Faculty psychologists change questions spuriously into answers by animating the operations of the mind or abilities, activities or other dispositions. Such descriptive terms become hypostatized, and take on the qualities of an occult agent, cause, or power. For example, Thomas Reid moves directly from the description of classes of mental operations to the postulation of a faculty or power as active agent: 'The words power and faculty, which are often used in speaking of the mind, need little explication. Every operation supposes a power in the being that operates; for to suppose anything to operate, which has no power to operate, is manifestly absurd.[2] Gall's faculty psychology confuses 'function' as a classificatory concept for a number of related behaviours, with the cause or causes of those behaviours.When Gall explains that a woman loves her children very much because a large cerebral organ produces a strong faculty of 'love of offspring', or that a man can reproduce very easily verbal material that he has heard or read because he has a highly developed 'memory for facts', he is giving no more of an explanation than Molière's physician, who explained that opium produces sleep because it has a soporific tendency. However, in rejecting Gall's faculties as explanations one should not ignore the importance and novelty of the questions he begs and the classification of functions which he offers. It is possible to accept his approach to the functions of the brain and even some of the functions themselves as novel problems for psychological analysis, without lapsing into the circularity of faculty psychology.Leaving aside the problems raised by the form of Gall's psychology, it could easily be shown that each of the functions which Gall proposed as basic has emerged again as a function investigated by modern brain and behaviour research, using the concept and techniques of cerebral localization. There is no point in producing a detailed list of these functions, since variations in the operational meaning of the terms would reduce it to an elaborate pun. However, the point should not be missed that the fundamental functions which Gall derived from his naturalist observations and which were ridiculed as fanciful by subsequent1 Riese, 1959, pp. 22,24.2 Reid, 6th ed., 1863, I, 221.23investigators have re-appeared as problems in recent research. A few examples should suffice: sexual instinct, maternal behaviour, self-defence, carnivorous instinct, verbal memory, sense of locality, language, music, numerical ability, conscience-each of these has had its modern investigators and localizers.How are the Functions Localized?Except for his purely neuroanatomical discoveries, the only indisputable contribution that Gall made to the history of science is the concept of cerebral localization. It is this concept that makes Gall's work classical, in that all subsequent research involved taking some stand on the issue of whether various functions are localized in specific parts of the brain. Some investigators conducted much of their work in explicit opposition to cerebral localization, some accepted a more or less modified form of the doctrine as their basic assumption about the functional organization of the brain, and others confined their use of the concept to a technique for either pathological and clinical studies, or physiological research. The role which this concept played in subsequent clinico-pathological and physiological research in the work of Broca, Fritsch and Hitzig, Hughlings Jackson, David Ferrier, and other investigators in the nineteenth century and its continued use up to the present, will be discussed in the following chapters. However, one judgement by a later investigator may briefly indicate the debt of later workers to Gall's initiative.The minute anatomy of the convolutions was unknown in the time of Gall, and he based his phrenological theories rather on the external prominences of the skull-on cranioscopy — than upon a careful study of the convolutions to which these prominences corresponded, and although his conclusions must be considered in many instances arbitrary and hypothetical, still I would say, 'Let not the spark be lost in the frame it has served to kindle,' for in spite of all that has been said against Gall, and all that has been written in depreciation of his labours, beyond all doubt his researches gave an impulse to the cerebral localization of our faculties, the effect of which is especially visible in our own days; and I look upon his work as a vast storehouse of knowledge, and as an imperishable monument to the genius and industry of one of the greatest philosophers of the present age. The localization of cerebral function may be said to have received the first real impetus from Gall, for before his time no such attention was given to the subject as deserved the name of systematic study.[1]1 Bateman, 2nd ed., 1890, p. 319. Cf. the judgement of Wm. Lawrence quoted above on the first page of this chapter.24For the present, I should like to confine my attention to the role which the concept of cerebral localization played in Gall's psychological and anatomical investigations. The main point that will emerge from this analysis is that while the concept of cerebral localization was central to his theory, direct investigation of the brain and specification of clearly defined areas on the cortex played almost no part in his work. Gall had elaborated his four basic principles and many of the details of his theory before the first publication of his views in 1798.[1] J. G. Spurzheim, his pupil and colleague from 1800 to 1813, says that Gall had 'not yet begun to examine the structure of the brain' by 1800.[2] He had been elaborating his views about the functions of the brain as early as 1792, and gave a public course on the subject at least as early as I796. His views at that time included the argument that the brain is necessary to the manifestations of mind, 'of the plurality of the mind's organs, and of the possibility of discovering the development of the brain by the configuration of the head'.[3] 'Between 1800 and 1804 he modified his physiological ideas, and brought them to the state in which he professed them at the commencement of our travels' (1805).[4] Gall had met an intelligent woman with extreme hydrocephalus whose intellectual capacities were apparently unimpaired and had reached the conclusion that 'the structure of the brain must be different from what it is commonly supposed to be. He now felt the necessity of examining the mind's organ anatomically'.[5] The neuroanatomical investigations which he then began to make with the help of Spurzheim, and which were the basis of his well-deserved reputation for dissection and discovery, were completely unrelated to his doctrines of function and his organology. They were concerned with dissection method, subcortical and medullary structures, the nuclei of cranial nerves, the decussation of the pyramids, the continuity of grey matter with the white fibrous matter,[6] and a very odd doctrine about the unfolding of the hemispheres in hydrocephalus. His neuroanatomical work was not inconsistent with his organology, but was irrelevant to it. The anatomical exposition in his 1808 memoir, the first volume of his Anatomie, and the anatomical debates in the final volume of The Functions of the Brain are not integrated conceptually with the detailed exposition of his psychology and craniology-organology in the rest of his works.[7]1 Gall, 1835, I, 6-19. 2 Spurzheim, 1826, pp. ix-x.3 Ibid., p. ix.4 Ibid., p. x.5 Ibid.6 See Temkin, 1953.7 Flourens stresses this point in his critical work on phrenology. In his discussion of the memoir which Gall and Spurzheim submitted to the National Institute in 1808, he says that25The key to this very baffling discontinuity in Gall's exposition is that here, as with his naturalist principles, his functional viewpoint, and his critique of philosophical psychology, he enunciates important principles which he was unable to carry out in practice. Thus, Gall insists on connecting anatomy and physiology (which, for him, means psychology) in principle, since the brain is the organ of the mind, but he cannot demonstrate the details of the relations between brain and mind. When the Committee of the National Institute reviewed the memoir submitted by Gall and Spurzheim, they discussed the anatomical findings and conclusions, but insisted that it was not within their province to connect these with Gall and Spurzheim's physiological doctrine of the special functions of the different parts of the brain.[1] Gall was very indignant about this decision, since he (I think rightly) took them to be separating anatomical studies from physiological studies in principle. The Committee had said that Gall's anatomical discoveries came within their province, but that the physiological doctrine 'in no way comes under the cognizance of the class, since it ultimately depends upon observations relative to the moral and intellectual disposition of individuals, which certainly are not within the sphere of any academy of sciences’.[2] To Gall this separation of the sciences of anatomy and physiology was founded on the assumption that the functions of the brain 'have no immediate and necessary connection with its structures.’[3] His reply is based on the organ-function paradigm that had become central to his thinking: 'Can any one advance that motion and secretion have no relation to the organization of the muscles and viscera; and that digestion and the circulation of the blood have not an inseparable affinity with the stomach and the heart? etc.[4] The principle at stake was whether the brain was the organ of the mind. To rule out investigations of the mind connected with the study of the brain was to deny this fundamental truth.
Gall considered this matter of principle to be quite a different question from that of the proper method of discovery of the functions of
it does not contain 'one word of special anatomy, of secret anatomy, of what might be called anatomy of the Doctrine; or, in other terms, and as it would be expressed at the present day, of phrenological anatomy. . . . The anatomy of Gall's memoir is nothing but very ordinary anatomy . . . it is sufficiently clear that, whatever side we take upon these questions [i.e., anatomical debates on conventional issues about the organization of the brain in which Gall played a leading part], his doctrine assuredly would neither gain nor lose any thing'. (Flourens, 1846, pp. 70-71. Cf. pp. 72-4.)
1 Tenon et al., 1809, pp. 36-7.
2 Ibid., pp. 36-7.
3 Gall, 1835, VI, 29.
4 Ibid., VI, 30.
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the brain. In practice, 'the discovery of the functions of the brain is made independent of the knowledge of its structure . . .[l] There is no doubt in Gall's mind about the priority of behavioural studies in his own work.
The knowledge of the functions has always preceded that of the parts. It is, also, as I have said elsewhere, without the aid of the anatomy of the brain, that I have made all my physiological discoveries; and these discoveries might have existed for ages, without their agreement with the organization having been detected.[2]
A detailed analysis of the history of discovery of each of his fundamental functions supports this description of his method. In no case does anatomical information play anything more than a confirmatory role in his elucidation of the functions. He presents detailed arguments containing both in principle and historical objections to show that the study of structure has never led, and never could lead, to a knowledge of the functions of the brain. He holds this position against the findings of simple dissection, neuropathological studies, mutilations (ablations) and comparative anatomy.[3]
Gall's argument against morphological and experimental researches on the brain is based on the view that they cannot themselves give a knowledge of the functions of the brain, and that without such knowledge they are meaningless. The reason that the attempts at cerebral localization before his work had failed was because no attempt had been made to find first the 'radical, fundamental, primitive faculties'.[4] There could be no cerebral organs for the abstract, metaphysical, speculative faculties of the philosophers. No amount of philosophical speculation or of morphological investigation could be of the slightest use until the fundamental faculties were discovered from observation of the habits of animals and of the moral and intellectual characters of individuals in nature and in society. Instead of conducting minute researches on brains, physiologists must first gain a knowledge of the 'diversity of mechanical aptitudes, instincts, propensities, and faculties, which constantly attend this variety of organization'.[5] In the light of the extreme physiological reductionism that occurred in the last three decades of the nineteenth century, one must acknowledge that Gall's
1 Gall, 1835, VI, 29.
2 Ibid.' II, 25-26.
3 Ibid., III, 88-104.
4 Ibid., III, 82.
5 Ibid., VI, 192.
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view of the priority of behavioural and psychological investigations was ignored.[1]
Thus there was no doubt in Gall's mind that we must first know the functions before we can learn anything important from the direct study of the brain. He is not entirely consistent, though, on the role of brain studies after the functions have been elucidated by behavioural studies. In his own special doctrine he uses anatomical, pathological, clinical, and comparative findings when they confirm his psychological findings. As the founder of craniology, he does not doubt that the correlation between a striking behaviour and a cranial prominence is telling him something about the brain. The point that he insists on is that one must first know the functions. If anatomical and experimental findings confirm his behavioural discoveries, all is well: they ought to do that.[2] If physiological findings are in opposition to anatomical findings, the issue is slightly obscure. Ordinarily, Gall is quite clear on this point. Consistent with his view that the brain is the organ of the mind, he takes the position early in his work that 'A doctrine of the functions of the brain, if it is in contradiction with its structure, must be necessarily false'.[3] However, in the conclusions to his last volume, written after vehement controversies with the experimental findings of Flourens, Rolando and others, and the publication of the anatomical findings of a number of comparative anatomists, Gall retreats from this firm stand and appears to betray his own fundamental thesis. A charitable view of the following quotation might be, though, that he is protecting his reputation against the day that he might be found a bad anatomist but a good psychologist. His conclusion is
That the fate of the physiology of the brain is independent of the truth or falsity of my assertions relative to the laws of the organization of the nervous system, in general, and of the brain in particular, just as the knowledge of the functions of a sense is independent of the knowledge of the structure of its apparatus.[4]
If it is understood clearly that Gall places anatomical investigations
1 It is interesting to note that in later work Hebb came forth with a position very similar to Gall's: 'a physiologically oriented theory of behavior must remain a psychological theory. It will have to employ constructs derived from behavior which could not have originated with neurological data, even if subsequently one finds a way of relating them to such data'. (Hebb, 1959, p. 635.) Gall would have agreed emphatically with Hebb that the direct study of brain function can never be a substitute for psychology, although he might have been less enthusiastic than Hebb in believing that it contributes essentially to psychology, except-Gall would have said-in principle and as confirmatory of psychological findings. (Hebb, 1959a, p. 269.)
2 Gall, 1835, VI, 80.
3 Ibid., VI, 30.
4 Ibid., VI, 237-8.
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as a secondary matter in his search for the functions, one can still ask to what extent he attempts to specify the localization of functions in the brain substance. In the first place, his localizations are confined to the cortex: to areas that could exert an effect on the conformation of the skull. In the second place, they are in all cases offered as a confirmation of a localization he had made in the belief that the cranium serves as a faithful cast of the underlying brain. It is always the brain that he is writing about, but given the faith he had in the craniological hypothesis, he was not systematic in actually looking at brains. His faith in cranioscopy became so complete that at one point he says that 'There is no other possible means of discovering the functions of the cerebral parts'.[1] Nor do his writings indicate when he was looking at brains and when he was inferring the existence of the cerebral organ from prominences on the overlying cranium. He occasionally specifies an observation made directly on a brain. He assure us that each time he checked the brain against the cranium, his findings on the cranium were confirmed.[2] But when he specifies the convolutions which make up an organ for a given function, one often has no way of knowing whether the evidence for this included direct observations on brains. He merely specifies the convolutions by a number of one of the brains in his atlas. He does not pretend to be able to 'circumscribe exactly the extent of each organ'.[3] His organs do not divide according to the convolutional patterns of the brain.[4] Gall was content to specify the areas and to admit freely that he neither knew the functions of all the cerebral parts nor the precise limits of those parts whose function he had specified.[5] He left the precise delimitation of the cerebral organs to future investigators and contented himself with saying that in discovering the functions of the brain he had made their task meaningful for the first time, and immensely easier.
The conclusion one reaches about Gall's work on localization is that he was more interested in the nature of the functions than in their localization, and that he had more to say about localization in principle than in practice. Finally, given the inability of later workers to confirm his craniological methods, the approach he took to direct observation of the brain leaves much to be desired. The principal merit of his work, then, is a conceptual one, not an empirical finding or set of findings. He drives home the point by constant reiteration and exemplification
1 Gall, 1835, II, 34.
2 Ibid., VI, 86. Cf. III, 25, where he answers his critics on this point.
3 Ibid., VI, 85-6, Cf. II, 249-50
4 Ibid., VI, 20.
5 Ibid., VI, 86.
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that 'the study of the organization of the brain should march side by side with that of its functions'.[1] By juxtaposing on nearly every page statements about behaviour to statements about the brain, and subsuming both into a naturalistic, biological framework, he created a way of thinking that future investigators with more precise techniques and an experimental methodology could follow and exploit impressively.
What has been said so far about Gall's views on neuropsychology has been concerned with the investigation of the functions of the brain. For Gall the functions of the brain was the behaviour of the organism, and he called their study 'physiology'. The science of functions addressed itself to the question of what the functions are. This conception of physiology seems foreign to the activities of most modern workers who call themselves physiologists, while Gall's activities and observations would be quite natural to a modern psychologist or ethologist. This is a matter of the state of physiology in Gall's day. Sir Michael Foster points out that as the hypothesis that animal and vital spirits are the cause of physiological phenomena was progressively replaced by the materialist concept of organs as machines and their actions as functions, there was a period when people were little concerned with how an organ produced a function and were content with 'the mere enunciation of the function as the chief end of physiological inquiry'.[2] If one asks what Gall had to say about how the brain functions as opposed to what are the functions of the brain, he has little to offer. Those who did oppose his attempt to discover the organs and their functions sometimes objected that until he could specify how the brain produced its functions in the same way that one could specify how the stomach produces digestion, he had no doctrine of the physiology of the brain. The implication was a dualist one: that since the phenomena of the brain were of such an entirely different order from the phenomena of experience and behaviour, the task was an impossible one.[3] Gall's answer was that with many organs one can only specify the dependence of the function on the integrity of the structure. One can specify the structure, its function and their covariances concerning the stomach, the blood, the semen, and the external organs of sense. 'Thus we know the facts, and some conditions which are requisite in order that these facts should occur; but the why and the wherefore are almost always unknown to us. Well, this is precisely as much as we know in regard to the intellectual faculties and moral qualities’.[4] His science was in no worse a situation than other
1 Gall, 1835, II, 46.
2 Foster, 1885, p. 10.
3 Gall, 1835, III, 70-1. Cf. below, pp. 80-2.
4 Ibid., III, 74-5
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branches of physiology. Given the state of physiology at the beginning of the nineteenth century, Gall's reply was quite fair and proper. He not only had almost nothing to say about physiology as we now understand it-the study of material and efficient causes-but he felt no need to be embarrassed about the fact.
Neuroanatomical and neurohistological studies had not advanced far enough to place any effective 'givens' in the path of how Gall chose to view the functional organization of the brain. There were no awkward facts that any theory had to explain. The divergence since Gall's time of what is known about the fine structure of the brain and the language used to describe it, from knowledge and descriptions of behaviour and experience, makes his position enviable. The problem of relating the language of psychology to the language of physiology and of finding some means of translating between these two universes of discourse did not exist for Gall. Subsequent advances in the study of the brain have made the task not easier but immeasurably harder. Gall's problem, as he saw it in 1798, and throughout his work was almost absurdly simple. 'As I suppose a particular organ for each one of our independent qualities, we have only to establish what are the independent qualities, in order to know what are the organs which we may hope to discover'.[l] He says very little more about the nature of the cerebral organs than that they constitute 'the material condition which renders possible the exercise or the manifestation of a faculty'.[2] He does specify that the organs are made up of 'a greyish, pulpy, or gelatinous substance'. This substance constitutes the hemispheres of the brain and is the ramification of the various fibrous bundles (our fibre tracts of white matter). The variations in the size of these ramifications depend on the size of the nervous bundle. These determine the activity of a given cerebral organ and thus the importance of the corresponding faculty in the behaviour of the organism. Gall does not develop this view further and does not attempt to connect it with his detailed neuroanatomical investigations.
Since there were no 'givens' from detailed neuroanatomical studies of the cortex, Gall could allow his method and sources of data to dictate the categories which he derived for relating brain function to behaviour. The kinds of behaviour which were the sources of his fundamental categories came from the extremes of society: marked propensities, talents, monomanias, and animal activities. From these he derived a faculty psychology. Then, from the context of his craniological method
1 Gall, 1835, I, 14.
2 Ibid., I, 234.
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and belief in it as an accurate reflection of the structure of the underlying brain, he could argue that since we analyse behaviour in this way, the brain must be organized to produce it in this way. Thus, to the modern physiological question of how the brain is functionally organized to produce behaviour, he would have answered 'By having an organ that produces (or is the material instrument of) each kind of behaviour which we observe to be fundamental. Each category of behaviour has its own organ'. This is a simple one-to-one correlation. Since his data were correlation of striking behaviours with cranial prominences, the direct application of his psychological categories to the brain seemed perfectly legitimate.
The history of brain and behaviour research in the present century can be seen as a progressive abandonment of faith in a one-to-one correlation between the categories of analysis and the functional organization of the brain on the one hand, and the analogous variables in behaviour on the other. The simple faculty-organ view has given way to a progressive divergence of the understanding of behaviour from that of the structural organization and physiological functioning of the brain.
In the last three decades of the nineteenth century the one-to-one view was revived but the relative emphases on psychological and brain categories were almost completely reversed. Instead of allowing psychological categories to dictate to the brain, the categories of physiological analysis dictated that all thought and behaviour were the result of the association and combination of sensory and motor substrata. Gall's organology, which was eminently suited to a faculty psychology, was replaced by a different view of cerebral localization which referred to cerebral areas for each of the classical sensory modalities and for movements. Within this scheme certain 'centres' for specified movements, and punctate localizations for specific sensory modalities were determined. The complex functions which Gall had made the basis of his faculty psychology were abandoned, and attempts at explaining complex psychological phenomena were confined to the thesis that the normative intellectual functions of thought, volition, speech, etc., were the complex products of sensory and motor elements. This work emerged from a combination of association psychology with clinical and physiological interests, and the view of mental processes was explicitly based on the prevailing conception of the constitution of the cerebral hemispheres as consisting of centres related to sensory and motor tracts.[1]
1 Ferrier, 2nd ed., 1886, Chapter 12.
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Gall's localizing assumption became a methodological tool for the discovery of critical cerebral determinants for given behaviours under controlled conditions. If a behaviour ceases to occur on ablation of a given structure, the inference should be restricted to the conclusion that that portion of the brain is a necessary condition for the performance of the behaviour under the conditions of the experiment. From this initial datum, it is necessary to go on to discover the remaining portions of the nervous system which, in combination, are sufficient to produce the behaviour. This requires both the working out of a complicated set of functioning neural circuits, each part of which is necessary for the behaviour to occur, and the combined use of stimulation, ablation, degeneration, and recording techniques. This is the neurophysiological aspect of the current version of the problem that seemed relatively simple to Gall.
The behavioural aspect is at least as complicated, since it requires the specification and control of environmental conditions which provide a valid test of the function in question. The series of experiments which meets this requirement must combine in such a way that all of the operational meanings of the function are tested and related to the neural circuits necessary and sufficient for its production.
The difficulties involved in the two aspects of the problem and in integrating the data from the two universes of discourse can be gathered from a reviewer's comments on a recent symposium on Brain Mechanisms and Learning.
It is clear that technical skill and methodical sophistication in analysing brain-behaviour relationships are steadily rising. A comparison of this work with research of say, 25 years ago, seems staggering. And yet the neurological basis of learning remains mercurial. [This is partly due to the complexity of the learning process.] More fundamental, perhaps, is the marked difference in units of analysis appropriate to the two domains-the neurological units being bursts of impulses occurring in a brief period of time, the behavioural units being turns in a maze or a memory of an event that occurred years previously. The operations relating the two are, for the most part, missing, so that research must content itself with either simple correlations — the hippocampus gives 5 to 6 c.p.s. wave-trains as an animal approaches food-or a listing of necessary neurological conditions (rarely has it been possible to state precisely the sufficient conditions) for certain forms of behaviour to occur-the monkey must have two intact frontal lobes to perform delayed response efficiently. [1]
Gall's method of inferring functions directly from behaviour and its
1 Weiskrantz, 1962, pp. 125-6.
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one-to-one correlation with a portion of the brain seems a long way from the logical and empirical complexities of current methods and concepts.
How can the Functions and their Localizations be Determined?
Many of the elements of Gall's method for discovering the fundamental faculties and the seats of their organs have already been mentioned. However, as a preliminary to contrasting his method with that of Flourens and the experimental physiologists, it may be useful to examine the sources of data he employed purely as methodology and independent of the nature of his psychology and psychophysiology. It has been pointed out that he had nothing but ridicule for the introspections and speculations of the philosophers, for the physiognomy of Lavater,[1] and for the investigation of the brain independent of the study of behaviour. Gall was quite self-conscious about the methodology he followed and spells it out in detail. It is clear from his description of the history of discovery of each of his faculties (which he provided for all but three of the twenty-seven fundamental faculties), that he actually used the methods that he said he did. Whatever reservations one may have about the craniology involved in almost all these methods, it is important to remember that all of them were empirical methods and that this was a new feature in psychological investigation. Gall lists nine methods:[2]
1. Correlation of propensities, sentiments, and talents drawn from common language, with cranial prominences. When he met or heard of a man or animal endowed with a striking talent or propensity, he sat out to determine if this remarkable behaviour was the work of nature: a truly fundamental faculty. (The criteria for deciding which remarkable behaviours referred to fundamental faculties will be considered separately.) The main criterion was that it be manifested independent of the other characteristics of the individual or species. When he found men or animals with an eminent talent or propensity he examined the form of the head for a cranial prominence. He collected and compared as many such correlations as he could find.
2. Counter-proof. Individuals who had a moderate degree of a given quality or none at all were examined for lack of the corresponding cranial prominence.
1 See Gall, 1835, V, 261-6; I, 17-18. Gall proposed a study, Pathognomy, which was to replace physiognomy. It was perhaps his least fortunate idea and its 'findings' go far beyond the most flagrant excesses of cranioscopy. (See Ibid., V, 266-94.)
2 Ibid., III, 108-130.
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3. Correlation of marked cranial prominences with the faculties and qualities of individuals. When Gall saw a striking head prominence he would engage the individual in conversation to determine his propensities and talents. He travelled to schools, foundling homes, hospitals, prisons, and lunatic asylums, and obtained information on remarkable heads and remarkable talents wherever he could.
4. Collection of head casts. Gall collected and measured the casts of hundreds of individuals remarkable for either their talents and propensities or their cranial conformation. More or less systematic comparisons were made of like faculties and like skulls.
5. Collection of crania. When Gall found a common character in ten or twenty casts or skulls, he combined these data with those obtained from other methods.[1]
The above are the principal methods Gall used. Of the rest, he says, 'The following methods have assisted me less in discovering the fundamental qualities and faculties, than, in proving their discovery.’[2]
6. Correspondence between skull and underlying organ. After Gall had marked out a number of protuberances on the skull, he then began to see how far these prominences corresponded with the underlying brain. He assures us that no exceptions were found to such correspondence in sound or middle-aged brains.
7. Comparative anatomy and physiology; natural mutilations of the brains of animals. Gall argued that nineteen of the twenty-seven fundamental faculties were shared between men and animals. After the fundamental faculties had been discovered in man, he turned to species differences in the behaviour and crania of animals. By natural mutilations, Gall meant that the step-wise addition of organs and faculties in the 'chain of being' provided a more trustworthy method of discovery than the artificial mutilations of such experimental physiologists as Flourens.
1 Gall's zeal for collecting skulls and busts was notorious and the subject of many contemporary jokes. He made collections both in Vienna and Paris, and parts of both still exist. By 1802 he had collected more than 300 skulls and 120 casts. Most of this collection remained in Austria. The collection which he made in Paris contained over 600 pieces which were bought from his widow (in exchange for a pension) on the advice of Cuvier and Saint-Hilaire, and placed in the Musée de I'Homme in Paris. The collection is still there, although its catalogue was removed by the Germans in I941. A recent attempt at reconstructing the catalogue shows that it contained over 70 criminal busts, and those of various talented people. A complete catalogue of the collection appears in the Phrenological Journal and Miscellany 6, 1829-30, 480-99; 583-602; and 7, 1831-2, 27-36; 181-5; 250-3. Its existence was unknown to Ackerknecht and Vallois at the time they made their reconstruction from a manuscript found at the Musée de I'Homme. (Ackerknecht and Vallois, translated St. Léon, 1956, pp. 37-86; Ackerknecht, 1956, pp. 294-308, provide an index to their reconstruction.) Further information on phrenological collections in France and Britain is given in Laycock, 8th ed., 1859, p. 563.
2 Gall, 1835, III, 120.
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The large number of observations on the behaviour of animals included in Gall's work give him a legitimate claim to be the writer of the first systematic animal psychology, seventy years before the work of Romanes which is usually given this distinction. Gall was as convinced of the continuity of animal and human functions as any post-evolutionary animal psychologist, and a number of his fundamental faculties drew heavily on observations of animals for their evidential support.
8. Accidental mutilations. Gall rejected experimental ablations, but he was prepared to accept evidence from the accidental injury to a part of the brain as confirmatory evidence for a localization that was already established on other grounds. However, he would accept neither experimental ablations nor clinico-pathological correlations as evidence for a localization that had not already been established. He offered reasons both practical and in principle why nothing could be learned from such experiments used alone.
9. The succession and arrangement of organs. After the faculties and their organs had been discovered by strictly empirical methods, Gall believed that their harmonious arrangement in the brain constituted another proof of the validity of his discoveries. He found the faculties common to man and animals in one part, those unique to man in another, those of indispensable function in the most protected places, and those of like function adjacent to one another.
Other sources of data which Gall fails to mention in his methodological exposition include quotations from famous authors, paintings and busts of doubtful authenticity, and anecdotes from any source. In practice, Gall's interest in a given faculty or propensity was almost always derived from a striking individual or a cranial prominence. It is this correlation which forms the basis of most of his faculties, and none was discovered without the aid of cranial prominences.
The most serious problem raised by Gall's method was the determination of which classes of behaviour represented fundamental faculties, and which were merely the result of combined activity of other, fundamental faculties. In raising this issue, Gall was addressing himself to the most perplexing problem in psychology: its lack of an agreed set of units of analysis. Gall believed that he had solved this problem, and his solution was very sophisticated by modern standards: isolate the variable by observing its pathological manifestations, and its changes independent of other functions.[1] There was hardly a single
1. For the twentieth-century version of this approach, see Spearman, 1927; for the relations between this work and Gall's, see Spoerl, 1935-6.
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faculty of Gall's which did not raise the problem of whether or not it was a fundamental, primitive, radical function. He had rejected the philosophers' faculties precisely because they were not determinate for individual behaviour, and he had to show that his own functions were. Gall sought to find an extreme manifestation of each of the faculties he thought to be fundamental, and to find it varying independent of others by its development at a different period from others (e.g., instinct for propagation), its striking appearance in a character that is otherwise unremarkable (e.g., a poet or musician who is not remarkable in any other sphere of life), its activity while others are paralysed (e.g., an idiot who is talented at mimicry), its difference between the sexes (e.g., caring for offspring), and its difference between species (e.g., the constructive talents of beavers and spiders compared to horses and cows).[l] Gall's most trustworthy criterion is the exaggeration of a given quality in geniuses and maniacs. Thus, he argued that there is a monomania for each of his faculties, and searches the writings of Pinel for cases that could be construed as insanity involving one of his fundamental faculties. It is in their extreme activity that the faculties most readily reveal their natural language, and Gall thus draws heavily from the extremes of society: criminals, prodigies, geniuses, lunatics. 'In conformity to principles, I have more than once announced, we may infer, that when, in disease, some particular quality is manifested in a much higher degree of activity than the others, it is fundamental'.[2]
Given such sources of fundamental faculties, Gall sometimes has difficulty in specifying the role the faculty plays within the normal range of behaviour. He preferred to leave some doubt about the normal function of a given exaggerated manifestation than to draw premature conclusions.[3]
The structure of Gall's theory can be seen as a series of one-to-one correspondences:
Gall observed data of classes 1 and 4 and went on to argue to 2 and 3. The faculties were the only unobservables in the theory, but Gall was often unable to obtain direct evidence about the cortical organs, since most of his observations were made on living organisms. His usual
1 Gall, 1835, III, 133-5.
2 Ibid. IV, 162.
3 Ibid. V, 248.
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procedure was to infer the existence of both 2 and 3 from an observed correlation of 1 and 4. It appears from his writings that Gall was extremely predisposed to see a cranial prominence or large cerebral organ when he already had evidence of a striking behaviour. In practice, the falsifiable part of the theory was the correlation of striking behaviours with cranial prominences. Gall's failure to falsify this covariance can be explained partly by the difficulty of palpating the living skull, but the main problem lies in his anecdotal method. He sought cases confirming his theory, and each new case strengthened his belief that he had found a valid correlation. This selection of cases is the most serious danger of the naturalistic and anecdotal methods which he employed. The problem of selecting cases for the method of clinico-pathological correlations remained until sophisticated statistical methods of case selection and suitable control procedures were developed in the present century. In Gall's day, the only substitute available for the anecdotal method was that of experiment, and this was the method which Gall rejected, while Flourens and later workers used it to provide information about cerebral localization of functions which Gall failed to discover.
Before turning to the contrast between Gall's method and that of the experimentalists, it is worth noting how impressive Gall's achievement would have been had his simple one-to-one correlations proved valid. First, psychology would have 'become possessed of an apparently complete list of human powers, faculties and tendencies, in terms of which the whole human mind could be fully and accurately described'.[l] Secondly, the problem of the functional organization of the brain would have been solved as the result of a single discovery. Finally, it would be possible to diagnose individual character and ability at a glance, eliminating the need for further personality psychology, psychology of individual differences, and vocational guidance and selection.[2]
Gall's Critique of the Experimental Method
Gall's simple one-to-one correlations between cranial prominences and striking behaviours did not prove to be the key to the functions of the brain or to its functional organization. The simple and obvious answer to why this was the case is that the craniological hypothesis was wrong, and investigations based on this hypothesis could therefore lead only to error. Gall has been praised for his insistence that the determination of the functions of the brain and the seat of their organs
1 Flugel, 2nd ed., 1951, pp. 37-8.
2 Ibid., p. 38.
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was a problem which could be satisfactorily answered only by observation, and that it was the job of the naturalist or physiologist to make such observations. On this issue, as with so many others, one finds Gall advocating something in principle which he was unable to carry out satisfactorily in practice. Gall's naturalism must be viewed in two ways. In the light of the speculations to which he was reacting, it was an immense step forward. The application of a consistent naturalism to man was a new approach in the first quarter of the nineteenth century. One is thus impressed with Gall when he insists that 'The naturalist, above all, is the slave of nature; he ought to know what is; afterwards he can give himself up to his vain desire of knowing why, what is, is, as it is'. [1] Or that he has 'conducted my reader by a path to which nature herself had directed me'.[2] 'I devoted myself entirely to observation, waiting patiently and resignedly for the results it would bring me.[3] Looking back from Gall to earlier workers, these statements are impressive. However, the second view one must take is forward from Gall, and it is here that his version of naturalism led him deeply into error, and was superseded by the experimental and control procedures that he rejected. Once the necessity for observation is established, the relative merits of the anecdotal and experimental approaches begin to emerge.
The striking thing about the craniological technique is not that it is based on an absurd assumption. The belief that the importance of a function was reflected in the size of its cerebral organ-which, in turn, determined the conformation of the overlying cranium-was a perfectly plausible hypothesis given the state of anatomical and physiological knowledge in the first decades of the nineteenth century. The striking thing is that this hypothesis was not found to be untrue by the phrenologists, that many thousands of observations were gathered in support of it, and that phrenologists are still gathering such evidence and being convinced by it. The explanation of the establishment and perpetuation of the evidential basis for craniology lies in the lack of rigour with which Gall's methods were applied. Gall was deceiving himself in claiming to be the slave of nature, waiting patiently for the results brought by nature or found along the road on which she conducted him.[4] In doing so he was attempting to ally himself with a naïve inductivist view of scientific method, the so-called true Baconian
1 Gall, 1835, III, 28.
2 Ibid. IV, 141.
3 Gall, 1822-25, III, 169. (Quoted in Ackerknecht and Vallois, 1956.)
4 E.g., Gall, 1835, III, 264.
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method of gathering facts from which inductions emerge. This view of scientific method neither represented Bacon accurately, nor did it truly describe the activities of any scientist. Gall's own description of his methods shows how he sought certain kinds of facts in the light of a preconceived hypothesis (which he had initially derived from a naïve induction in his childhood). But even if Gall had applied his own method rigorously, the inaccuracy of the craniological technique would have soon become apparent. His detailed presentation of the discovery of the faculties and their organs shows that he used all the methods mentioned, but that he did not apply each method to each faculty. He drew data from each method in so far as it was found to support his initial hypothesis. In short, he sought only confirmations. It is not his naturalism that is at fault; it is his anecdotal method and his standards of evidence.
It may help us to see both the plausibility and the error of his anecdotal method if a sample argument is given. Gall's presentation of the 'carnivorous instinct' or 'disposition to murder' is one of the fullest of the twenty-seven faculties.[1] The discovery of this fundamental faculty was based on two findings. In comparing the skulls of animals he noticed a consistent difference between carnivorous and frugivorous species, i.e., that 'in the carnivora, there are cerebral parts above and behind the ear, not possessed by the frugivora.......'[2] Second, the skulls of a parricide and of a murderer were sent to him. There were many differences, but 'there was, in each, a prominence strongly swelling out immediately over the external opening of the ear'.[3] He concluded that the brains of carnivores and murderers are developed in the same region and asked himself if this conformation was connected with the disposition to kill. His discussion of the natural history of the instinct in animals consists mostly of anecdotes about a particularly carnivorous lap-dog Gall owned.[4] In his presentation of the external appearance and seat of the organ in animals, he discusses the variation of the relevant prominence with the extent of carnivorous habits, and includes a discussion of a collection he had made of heads of dogs and cats. Over fifty species and their habits are mentioned. The evidence for the existence of a carnivorous instinct in man is as follows: The attitude of individuals toward suffering varies independent of education and class. He gives a series of anecdotes about individuals who delighted in witnessing the death of other men in executions and battles. These are
1 Gall, 1835, IV, 50-119.
2 Ibid., IV, 50.
3 Ibid., IV, 51.
4 Ibid., IV, 51-54.
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mingled with cases where individuals delighted in torturing animals and in seeing both animals and humans suffer and die. He then gives several cases of murderers who were notorious for their delight in senseless killing. Next, he appeals to history for the cruelties to Jews, the history of Rome, the Spaniards in the Americas, and the French Revolution. Finally, he turns to sadistic, cruel, and murderous tyrants, detailing the activities of Caligula, Nero, and Louis XI and listing others from Sylla [sic] to Henry VIII and Catherine de Medici. After this barrage of cruelties, he concludes: 'Who, now, will dare to maintain, that there is not in man an innate propensity, which leads him to the destruction of his own species? Where is the creature, that evinces more ferocity towards all other animals, not excepting his fellows, than man?[l] Turning to evidence for the independent activity of the propensity, Gall cites four cases of idiots who murdered, four cases quoted from Pinel of supposed murderous monomania, four cases Gall observed, and thirteen more culled from various written and verbal sources of insanity involving murder and sometimes mixed with suicide. In discussing the seat and external appearance of the organ in man he cites over twenty-five skulls in detail including those of many famous criminals which he examined and on which he found the requisite prominence. Finally, he cites the busts and paintings of famous murderers, all of which 'bear the outward mark of a cruel and bloody character'.[2]
This presentation of the data supporting one of Gall's faculties and its organ has been given in some detail so that there will be no basis for doubting Gall's accuracy, sincerity, or honesty when, in other places, he assures the reader that 'Since the discovery of this organ, hardly a day has passed, that I have not discovered confirmations either positive or negative of this truth'.[3] Or 'I have made thousands of observations on this subject, and have never found an exception'.[4] The point is that Gall's whole method was geared toward seeking confirmations. Where confirmations were concerned, he had almost no standards of evidence. His writings are filled with anecdotes about patients, famous people, animals, criminals, observations made by him, quotations from the scientific writings of others, reports in the press, quotations from literature. All are given equal credence so long as they support his views. It would not make sense to ask that Gall use control procedures and statistical methods, or conduct his work in the light of
1 Gall, 1835, IV, 68.
2 Ibid., IV, 118.
3 Ibid., V, 183.
4 Ibid., V, 197.
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a falsificationist view of scientific method, all of which are products of last quarter of the nineteenth century and have only come into their own in the last few decades. The anecdotal method which he used was the standard approach in human and animal studies until Galton (1884) and Thorndike (1898). Nor was measurement yet involved in such studies when Gall worked. What one can ask, though, is that Gall seek and treat counter-examples with the same seriousness that he did confirmatory findings, and that he apply the same- standards to apparent exceptions to his views that he applied to supportive evidence.
An example which illustrates both the lack of standards and the different treatment afforded to supportive and counter evidence is his approach to busts and other indirect evidence.
I have elsewhere said, that painters, draftsmen, engravers, and sculptors, sacrifice truth to erroneous notions of beauty, and endeavor to render less striking those uncommon forms, which they sometimes meet with in their models.[1]
Or
These two lengthened protuberances give to the superior part of the head, a great breadth and so singular a form, that painters, engravers, and sculptors rarely venture to present them in all their prominence.[2]
Thus, Gall is not worried if a representation of an individual with a striking propensity does not display the requisite prominence. On the other hand,
Still, there occur, from time to time, forms so striking, that the likeness absolutely depends on it, and then the artist is obliged, in spite of himself, to remain true to nature. In this way we obtain some faithful portraits of remarkable persons. The busts and portraits of Caligula, Nero, .........all bear the outward mark of a cruel and bloody characters. [3]
Finally, he argues from busts of Homer, Socrates, and Christ and (while granting that they were not taken from the originals while they lived) insists that since the sculptors must have used the greatest analogous men of their own times, craniology is still confirmed. When his expectations were not fulfilled, he had various means available for explaining away the facts. If the prominence were small, the propensity could exist because of the circumstances, e.g., a father murdering the
I Gall, 1835, IV, 117-18.
2 Ibid., V, 153.
3 Ibid., IV, 118.
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man who deflowered his daughter;[l] or it could be due to brain disease. A large organ can produce uncharacteristic behaviour because of its combination with the activity of other organs or with education, habit, example, etc.[2]
All we can confidently maintain is, that, caeteris paribus, a person who has this organ large, will be more easily induced to commit homicide, than one not naturally disposed to it by his organization.[3]
Gall's faith in his method led him to some quite ludicrous conclusions. In his discussion of the 'faculty of distinguishing the relations of colours' (which includes the talent for painting), he relates that
We were especially struck by a bookseller at Ansburg, blind from birth, who maintained, that it is not the eye but the intellect, which recognizes, judges, and creates the proportion of colours.[4]
Gall relates that this man was able to arrange coloured beads in a harmonious manner, that he felt a pain in the appropriate area of the head when doing so and that he displayed the appropriate cranial prominence.[5] The relationship which Gall develops between pride (hauteur) in man and birds which fly high in the air, depends on similar cranial prominences, and the extravagance of the analogy shows just how far he was prepared to go on the basis of bumps alone.[6] Because some of his organs were situated in areas lying on the underside of the brain in areas which touch the orbital plate, it was necessary for him to infer the size of four separate faculties from the conformation of the eyes and eyelids.[7] Finally, Gall was forced to deny the existence of the frontal air sinuses in most people in order to retain the cranioscopic evidence for his 'sense of locality'.[8] In his general remarks about the limitations of the cranioscopic method, Gall is often very modest and claims only that he can make valid inferences when the cranium does provide a faithful cast of the underlying brain. However, in his actual use of the method, he is very often uncritical in the extreme. Cranioscopy was Gall's most trusted method. It is ironic, therefore, that this is the only one of all his postulates and methods which has no analogue or direct descendent in modern work, except, of course, among practising phrenologists.[9]
1 Gall, 1835, IV, 108-10.
2 Gall, 1835, I, 244-6.
3 Gall, 1835, IV, 110.
4 Gall, 1835, V, 53.
5 Ibid.
6 Gall, 1835, IV, 170-81.
7 Gall, 1835, V, 4, 8, 19, 91.
8 Gall, 1835, IV, 263-4.
9 However, the narrower forms of physical anthropology can trace their ancestry to Gall's cranioscopy, both directly and via Hunt and Broca. See Ackerknecht and Vallois, 1956, pp. 27-8; Hunt, 1868-9.
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Beginning with Gall, phrenologists have had two characteristic reactions toward evidence. If it can be construed to support phrenology, it is proclaimed as confirmatory. If not, it is explained away. Gall dealt with a case of large, projecting eyes coupled with an unremarkable memory by suggesting that the large eyes might have been due to rickets or hydrocephalus.[1] Or, the talent might have been lost due to excesses or diseases.[2] In later years counter-examples were put forward more forcefully, and they were explained away. In Paris, a young boy was found with remarkable calculating ability and a depression where the prominence for number should have been. Broussais and Domoutier defended phrenology by explaining that his calculating ability was really a manifestation of other faculties acting in combinations.[3] A cast of half of Napoleon's skull which was unfavourable to phrenology was first criticised as a poor rendering and then answered by reference to parts of his skull which were not in the cast and therefore unavailable for examination.[4] Finally, it is reported that when Descartes' skull was found to be remarkably small in the anterior and superior regions of the forehead, where the rational faculties were localized, Spurzheim replied that Descartes was not so great a thinker as he was held to be.[5]
In 1857, G. H. Lewes called for phrenologists to 'cease for the present their accumulation of corroborative instances, and direct all their efforts to the accumulation of contradictory instances'.[6] This advice was friendly and was aimed at helping phrenologists to approach nearer to truths he felt they half grasped. It was not taken, and by 1871 he concluded that others had done the job for them with the result that precise scientific observations had shown that cranioscopy and its localizations did not correspond with the facts, and thus failed to gain general acceptance.[7] Nevertheless, phrenologists were undaunted in their search for confirmations, and attempted to appropriate any finding that in any way supported their theories. In i894, W. Mattieu Williams attempted to vindicate phrenology by citing Ferrier's motor localizations as confirmations of Gall.[8] 'If Ferrier had said that the leg is advanced “as in strutting", instead of "as in walking", his fidelity to Gall would have been quite perfect, and the significance of his description more intelligible.' The stimulation had been made at the point of Gall's organ
1 According to Castiglioni, exophthalmic goitre was known clinically in the first quarter of the nineteenth century, but Gall makes no reference to this alternative explanation. (Castiglioni, 1947, p. 781.)
2 Gall, 1835, V 13.
3 Lewes, 1857a, p. 668.
4 Ibid., pp. 669-71.
5 Ibid., pp. 671-2.
6 Ibid., p. 674. Cf. a similar sympathetic treatment by Carpenter (1846, pp. 520 ff.).
7 Lewes, 1871, II, 446-7. Cf. Haight, 1968, pp. 166, 188.
8 Williams, 1894, Chapter 9.
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of vanity.[1] Dr Bernard Hollander's works are filled with case material which 'confirms phrenology'.[2] If one meets phrenologists and has an opportunity to observe their absolute sincerity, some understanding and sympathy emerges for their insistence that (as one wrote to me) 'the only reason that I may appear enthusiastic is because day by day I find constant confirmation of it'.
Lest this appear a totally aberrant view held by credulous men who are unacquainted with standards of evidence in biology, it might be added that it was shared by Alfred Russell Wallace, co-discoverer of the theory of evolution by natural selection. Wallace read Combe's Constitution of Man as a young man (I844), and was convinced of the truth of phrenology and even of 'phreno-mesmerism', the belief that hypnotized subjects expressed the emotion appropriate to a given phrenological organ when the operator touched the requisite area on the cranium. Wallace conducted his own experiments and was satisfied with the evidence he obtained.[3] He had his head delineated by two phrenologists in 1847 'with such accuracy as to render it certain that the positions of all the mental organs had been very precisely determined'.[4] He remained convinced of the truth of phrenology, and explained Ferrier's findings as follows: 'The supposed "localization of motor areas" by Professor Ferrier and others, which are usually stated to be a disproof of the science, are really one of its supports, the movements produced being merely those which express the emotions due to the excitation of the phrenological organ excited'.[5]
The fact that Wallace could hold these views highlights the dangers of the naturalistic method. His own theory was based on the fact that many, many observations were explained by the hypothesis of evolution by natural selection. The more observations collected on the subject, the more the hypothesis was accepted. Both Darwin and Wallace used great numbers of naturalistic observations and pieces of anecdotal evidence to support the theory. The analogy between the theory of evolution and that of craniology is instructive. Granted, the standard of evidence was usually higher in the evolutionary work. But, logically it was in the same position as phrenology for most of the nineteenth century. It rested on naturalistic observations and a mass of anecdotes collected more or less systematically. Doubt remained whether the causal relations proposed by the theory were real, or only mistaken inferences from correlations reflecting the union of chance circumstances,
1 Williams, 1894, pp. 180-1.
2 Hollander, 1901, n.d., 1931.
3 Wallace, 1905, I, 234-6.
4 Ibid., 257-62.
5 Ibid., 262.
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until the theory was demonstrated by the experimental production of varieties by selection. Huxley had stressed this point and wrote (about 1887) ‘In my earliest criticism of the “Origin” I ventured to point out that its logical was insecure so long as experiments in selective breeding had not produced varieties which were more or less infertile; and that insecurity remains up to the present time.’[1] The difference is, or course, that experimental confirmation was forthcoming. Formally, the issue between Gall and Flourens is exactly the same as that involving evolution.
The whole issue of Gall's method, and of the subsequent history of phrenology, turns on the view which Gall took of his first finding, the correlation of ‘saucer-eyes’ and facility in learning by heart: 'I could not believe, that the union of the two circumstances which had struck me on these different occasions, was solely the result of accident.'[2] Gall and later phrenologists firmly believed that the correlations which they found between cranial prominences and notable behaviours, supported by data front each of the other methods they used, reflected causal relations. It has been clear since Hume that any inference from observed conjunctions to causality is an act of faith. The Humean concept of concept of causality views the most constant conjunctions in this sceptical way. Ample evidence of the inconstancy of some of the conjunctions observed by the phrenologists has been given above. Had they applied their own methods rigorously, this would have emerged. Since they did not, and since statistical methods were not available to them, the only alternative was that of experiment. Both naturalistic observation and anecdotes are recognized as valid sources of evidence , but can best be tested by controlling one variable and observing changes in another. The naïve inductive view of naturalists such as Gall was based on a misconception of 'true Baconian principles', for Bacon had stressed the importance of experiment as more revealing than mere naturalism. 'Human knowledge and human power meet in one; for where the cause is not known the effect cannot be produced. Nature to be commanded must be obeyed; and that which in contemplation is as the cause is in operation as the rule.’[3] Where effects
1 Huxley, 1900, 1, 170.
2 Gall, 1835, 1, 58-9
3 Bacon, 1960, p. 39. Concerning the study of natural history, Bacon says, ‘Next, with regard to the mass and composition of it: I mean it to be a history not only a nature fee and at large (when she is left to her own course and does her work her own way) - such as that of the heavenly bodies, meteors, earth and sea, minerals, plants, animals - but much more of nature under constraint and vexed, that is to say, when by art and the hand of man she is forced out of her natural state, and squeezed and moulded.....Nay (to say the plain truth), I do in fact (low and vulgar as men may think it) count more upon this part both for
46
can be produced by direct manipulation of a given variable, the inference from constant conjunction to causality requires much less of an act of faith. The methods used by the phrenologists allowed them to demonstrate the covariance between specifiable events, as can astrologers, some of whose predictions are also borne out by subsequent events. However, neither the phrenologists nor the astrologers can demonstrate that the relationships are causal by producing the effects by means of manipulation of the supposed causes.[1]
Why did Gall not avail himself of experimental method? He was not ignorant of this, nor, as his anatomical discoveries show, did he lack the technical skills required for carrying out experiments. In fact, Gall and Spurzheim, assisted by others, did conduct numerous experiments in response to Flourens' experimental determination of the function of the cerebellum in regulating locomotion, and of the equipotentiality of the cerebral hemispheres for the senses and intellectual functions. The results contradicted Flourens directly in some cases and were strikingly variable and unrepeatable in others.[2] Gall's reaction to these findings was to mount a full-scale attack on the use of the experimental method in nervous physiology. Before reviewing his argument one should note that this attitude of Gall's was in no way unusual. From the vantage point of the mid-twentieth century, Flourens' work marks the beginning of the experimental physiology of the nervous system which led to Fritsch and Hitzig, Ferrier, Munk, and Goltz, and to Sherrington, Franz, Lashley, and current workers. In 1822, the year Flourens published his first memoir, Magendie also published his experimental determination of the functions of the spinal roots. A measure of the unstable reputation of the experimental method, even at the time when it was beginning to give these impressive results, is the fact that the co-discoverer of the Bell-Magendie Law was himself opposed to animal experimentation on scientific and moral grounds and based his findings
helps and safeguards than upon the other, seeing that the nature of things betrays itself more readily under the vexations of art than in its natural freedom.' (Ibid., p. 25.)
1 Bain stressed the logical position in which phrenology was placed by its method, by reference to the chapter in Mill's Logic (Book iii, Chapter 22) on 'Co-existences Independent of Causation': 'He points out that such propositions demand uniformity without a break, in order to establish them in their generality. There must not be one single real exception, otherwise the rule is as completely void as if there were not one instance in its favour. Consequently, every instance that seems to contradict the general affirmation must be met and shown to be only an apparent exception'. Mill's example is the correlation of crows and the colour black and the possibility of a white one appearing. This criterion lends urgency to Lewes' objections cited above. (Bain, 1861, pp. 59-60)
2 Gall, 1835, III, 247-52. Cf. Gall, 1835, VI, 177-9.
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primarily on anatomy.[1] Bell wrote in 1823, 'Experiments have never been the means of discovery; and a survey of what has been attempted of late years in physiology, will prove that the opening of living animals had done more to perpetuate error, than to confirm the just views taken from the study of anatomy and natural motions....’[2] It has been pointed out that this view was shared by many eminent physiologists on the basis that the experimental physiology of the nervous system had shown very little up to that time.[3]
Gall had both technical and theoretical objections to the experimental approach used by Flourens. These appear in two parts of The Functions of the Brain: in the third volume he attacks Cuvier's laudatory review of Flourens' memoir of 1822, where the discovery of the regulatory function of the cerebellum is reported; volume six is devoted to answers to various criticisms of Gall's work which were brought by comparative anatomists and physiologists, and includes an answer to Flourens which, in this case, was based on a reading of Flourens' memoir itself [4] The issue between Gall and Flourens on method is particularly striking in that it involves the functions of the cerebellum, where their respective findings were unequivocal and sharply opposed. Gall's methods had revealed that this structure was the organ of the sexual instinct ('Instinct of Generation, of Reproduction; Instinct of Propagation'),[5] while Flourens, on the basis of surgical ablation experiments, concluded that it was responsible for the coordination of voluntary movements.[6] For Gall's critics, Flourens' discovery was an important basis for rejecting phrenology. Cuvier had high praise for Flourens. He describes the experiments in detail and concludes, 'This discovery, if repeated experiments, with all proper precautions, establish its truth, will do the greatest honour to the young observer whose work we have just analysed.’[7] He closes with the remark that Flourens presented new details and new facts 'which are as new as precious for science'.[8] After considering the controversy between Gall and Flourens on this issue, a contemporary English commentator concludes that Flourens' discovery and Gall's inadequate reply weigh heavily against the claims of phrenology. 'In the present state of matters, it appears to us no small proof of the validity of Flourens' doctrines, that so acute and so captious a controversialist, on a point
1 See Liddell, 1960, pp. 50-1.
2 Quoted in Olmsted, 1944, p. 117.
3 Ackerknecht and Vallois, 1956, pp. 22-3.
4 Cf. Gall, 1835, III, 97-100, 255-63.
5 Gall, 1835, III, 141-239. Gall et al., 1838, pp. 1-94.
6 Flourens, 2nd ed., 1842, pp. 37-43 and 133-41; 163n-4n.
7 Quoted in Gall, 1835, III, 255.
8 Ibid.
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so injurious to his system, has made so weak an assault, and has been reduced to such sorry subterfuges.'[l]
Since subsequent research has given such an unequivocal judgement in this controversy,[2] a review of the basis of Gall's opposition should be instructive. For Gall the issue was not only that of the function of the cerebellum but the legitimacy of direct experimental intervention into the processes of nature, particularly by ablation or 'mutilation'.
Gall's technical objections were: (1) The state of anatomical knowledge is too primitive for such operations: 'And how can we remove from the brain a single organ? Does any one know the commencement, the termination, or the limits of an organ?' [3] (2) Surgical techniques are not precise enough: 'Finally, how can we remove a part without affecting those that are contiguous to it? How can we remove the cerebellum, especially in the mammalia, without injuring the medulla oblongata and all the parts with which it communicates’.[4] (3) Surgical controls are too primitive to test the alternative hypotheses. The animal will not survive long enough to test Gall's view: 'Let us suppose that M. Flourens wishes to determine, by the ablation of the cerebellum, whether this part is or is not the organ of the instinct of generation, how will he be enabled to make the animal live sufficiently long, to decide whether the animal retains or has lost this instinct?'[5] This problem leads him to suggest that Flourens' findings may be artefacts: 'Is it astonishing, that the animal successively loses the faculty of flying, standing upright, of performing regular motions, of raising himself up when he is gradually ceasing to live?’[6] (4) Using the results of various experimenters, as well as his own, he argues, 'That it is impossible to perform exactly the