From phrenology to the laboratory

Introduction

A so-called ‘neuro’-turn has recently emerged in the humanities. Sociologists, literary theorists, economists and ethicists have all begun to evaluate the significance of nerve science in relation to the frameworks of their respective disciplines (e.g. Rose and Abi-Rached, 2013; Littlefield and Johnson, 2012). There is as yet, however, little agreement as to how such a turn might relate to practice and approaches that currently animate historical discourse.

On the face of it, the proposed development of a ‘neuro-history’ (i.e. a history that takes as its starting point present-day claims regarding the neurological basis of mind) promises much. Some, for example, have sought to adopt contentions regarding biological operations that underlie mental activity to offer revisionist accounts of large swathes of human history (e.g. Smail, 2008; McGilchrist, 2009). Yet, as others contend, this attempt to revise historical narrative is problematic, not least insofar as it positions historical skills and memory practices as subordinate to those relating to the brain sciences (Cooter, 2014).

Taking such collections as Salisbury and Shail (2010) and Jacyna and Casper (2012) as its point of departure, this article is intended as a contribution to an alternate approach to understanding the neuro-turn: examination of the ways in which claims regarding the nervous system have formed over time, and the role that these claims have had in the emergence of scientific culture more broadly. It thereby looks to identify how claims regarding the nervous basis of mind have come to inform and reflect present-day attitudes and beliefs. Specifically, it examines ways in which a particular notion of nerve and mind as correlated (the mid-19^th-century movement known as ‘physiological psychology’) participated in and helped inform the conceptualization of science as a primarily institution-based, laboratory-focused activity.

Physiological psychologists in Britain, ¹ I suggest, participated in the articulation of our current conception of science in one particularly notable way: they participated in the formulation of a rhetoric of scientific success that equated the institutionalization of science in laboratories with the economic advancement of the nation. The mid-19^th-century move by such figures as William Benjamin Carpenter, Herbert Spencer, Thomas Laycock, Alexander Bain and Henry Maudsley to identify nerves with intellect has been outlined in detail (e.g. Young, 1990[1970]; Hall, 1979; Jacyna, 1981; Danziger, 1982). As many of these analyses note, physiological psychology did not come to dominate psychological discourse at this time, and many of its proponents had fallen into obscurity by the 1890s (Buxton, 1985: 113–16). Nevertheless, I argue here, this movement has hitherto under-appreciated relevance for our understanding of the changes that occurred in the organization and practice of science at this time.

That an ideal of science as first and foremost an ‘experimental’ endeavour conducted in laboratories emerged over the latter decades of the 19^th century is widely recognized (e.g. Lenoir, 1997; Pickstone, 2000: 135–61). Though physiological psychologists did not generally conduct experiments themselves, physiological psychology, I claim, complemented the institutional aims of experimental practitioners involved in the articulation of this ideal. That it did so was at least in part due to a shift in emphasis that accompanied physiological psychological approaches to mind. Historians are well aware of the extent to which physiological psychologists concerned themselves with ontological questions regarding the nature of mind (and especially with the validity or otherwise of non-physiological characterizations of it) (R. Smith, 2013). What I will highlight here, however, is the extent to which, when faced with controversy among themselves, physiological psychologists came to privilege questions relating to epistemology over speculation regarding the nature or physicality of mind. Consequently, physiological psychologists came to value the practical skills associated with laboratories over less movement-dependent traits such as mathematical ability or literary eloquence. This change in rhetorical emphasis regarding the nature of learning, I argue, had particular relevance to debates regarding the status of science and the funding of laboratories.

To substantiate this claim, this article will address three points in turn: first, how physiological psychologists positioned themselves as authorities on mind; second, how they were able to present their beliefs as coherent despite disagreements among themselves; and finally, how their collective emphasis on bodily movement as critical to perception suited the needs of experimentalists arguing for the importance of their activities for national and economic well-being. In its demonstration of the connection between the articulation of physiological psychological ideas and changes in the conduct of science, it situates the nerve-centred psychology of mid-19^th-century Britain in the broader context of the emergence of experimental science as a politically and economically significant ‘way of knowing’ (Pickstone, 2000: 135–61). In conclusion, it highlights the relevance of these observations to the potential import of efforts to reconstitute historical scholarship in relation to the findings of neurological (rather than physiological psychological) science.

The physiological critique of phrenology

The 19^th-century association of mind with brain was initially centred around the popular movement of phrenology. Something of a rag-tag collection of beliefs and practices regarding the brain (van Whye, 2004: 170–4), phrenology was academically controversial. Between the arrival in Britain of the phrenology evangelist Johann Spurzheim in 1814, and the 1850s, Edinburgh professors consistently denounced his and his followers’ ideas. They maintained their critical stance despite repeated attempts to establish one or another version of brain-based psychology there (Shapin, 1975). Yet phrenological ideas spread throughout Britain. That they did so was largely due to their attractiveness to middle-class medics and proponents of ‘self-improvement’ such as Thomas Wakley and Robert Chambers. Phrenology seemed to its adherents both to demonstrate the capacity of newly comfortable individuals to improve their station, and to confirm the moral inadequacies of those who had not been able to do so (Cooter, 1984).

It is generally recognized that opposition to these emerging doctrines of self-improvement was often cast in terms of the moral hazard that, it was believed, was associated with the equation of mind and matter (van Wyhe, 2004: 140–64). Yet other kinds of critique of phrenology emerged at this time. Specifically, physiological psychological ideas also came to be ranged against the claims of phrenologists during the 1840s and 1850s. However, the physiological psychology movement was less concerned with challenging phrenologists’ association of mind with brain, than with the elaboration of such a link into a respectable claim that would be taken seriously by intellectual elites. For physiological psychologists, the chief concern with phrenological claims was not that they might be ontologically flawed, but that they were epistemologically unsophisticated.

Of the physiological psychologists noted in the introduction to this article, Carpenter was perhaps the most vehement critic of phrenology. Born into a family of prominent Unitarians, he sought unabashedly to utilize his growing reputation as reliable collator of physiological science to police the boundaries of acceptable and unacceptable knowledge. Carpenter’s commentary on knowledges considered marginal or academically unacceptable played a critical role in engineering his acceptance within the gentlemanly world of 19^th-century natural philosophy. Winter points to his cultivation of a reputable network of supporters in this regard (Winter, 1997). However, Carpenter founded his authorial claims on more than the acceptance of his name among polite society.

Phrenologists claimed to have been the first to truly acknowledge the organic nature of mind, elaborating a psychology that connected categories of thought generally accepted within moral philosophy with cerebral anatomy. Yet despite such claims, it would be a mistake to portray either the inherited categories of moral philosophy or the insights of cerebral anatomy as holding primacy in phrenological discourse. Rather, phrenological texts seek to reconcile a broadly moral philosophic or rationalist classification of psychological function with anatomical evidence relating to human brains (the organ presumed to be the ‘seat’ of consciousness) (Cooter, 1984: 126–7). Following the classificatory impulse of moral philosophy, phrenologists categorized the brain into different regions, each denoted by different psychological functions such as ‘conscientiousness’ or ‘individuality’.

Carpenter in his turn caricatured phrenology as a monolithic system concerned above all with this division of the brain into functionally distinct parts. His critique of it centred not on the plausibility of making such divisions, but on the functional identity of one of the most structurally distinct parts of the nervous system – the ‘cerebellum’ (located at the base of the rear of the brain). As they generally followed the schema devised by George Combe (itself derived from Gall), phrenologists tended to attribute the sexual function of ‘amativeness’ to this part of the nervous system. Carpenter disagreed. The first edition of his Principles of Human Physiology (1842) claims that even if the cerebellum can be said to be in some way identified with sexual desire, it also fulfils another, less (for-the-time) morally charged function: that of coordinating bodily movement.

Carpenter’s Principles insists on a need to conceive of human organs not as distinct elements of an individual human whole, but as entities that have developed from ‘simpler’ zoological manifestations. Though comparative anatomy did inform phrenological thinking (Price, 2012), Carpenter complains that phrenologists had ignored studies relating to ‘lower’ forms of life (Carpenter, 1842: 203–11). Regarding the cerebellum, they had, he suggests, ignored physiological experiments conducted on such animals as rabbits and chickens by the French physiologists François Magendie and Marie Jean Pierre Flourens (ibid.: 203–5; Young, 1990[1970]: 58–63). After they had ‘ablated’ (i.e. destroyed) this part of the nervous system in these animals, Carpenter notes, these physiologists had found that their experimental subjects were no longer able to move in a regular, coordinated manner. This, he suggests, presents clear proof of the coordinating function of this region of the brain. And even if such experiments could not be relied upon, a general comparison of the cerebella of more complex animals shows that the region appears larger in those animals that need to control many different moving parts (Carpenter, 1842: 203–5). Perhaps, Carpenter admits, the cerebellum is related to sexual function in some way. But what is certain is that it is also intimately if not pre-eminently involved in the coordination of muscular movement (ibid.). Phrenology had naïvely taken human anatomy as the starting point for investigation, and its allocation of cerebral function was consequently in urgent need of correction from scholars, such as himself, who were conversant in comparative anatomy and physiology.

A full-blown (albeit anonymous) attack on phrenology appeared from Carpenter’s pen in 1846. That year marked the publication of The Brain and Its Physiology by the prominent Manchester physician and one-time president of the Manchester phrenological society Daniel Noble (Cooter; 1984: 94–6). Noble had noted Carpenter’s claims, yet proclaimed his scepticism regarding the efficacy of comparative anatomical studies of nerves (Noble, 1846: 36–75).

In his unsigned review, Carpenter asserts the authority of comparative studies over those of the ‘mere human anatomist’ (Carpenter [attr.], 1846: 495). Noble’s ignorance regarding comparative anatomy and physiology means that he is not qualified to pronounce on the proper relations between nervous structure and mental function. A cursory survey of the field of zoology would have been enough to prevent him from reasserting such basic errors as associating the cerebellum with sexual feeling alone, and ignoring its coordinating function. Continued adherence to simplistic phrenological beliefs can only be the result of ignorance of comparative studies of nerves, which Carpenter feels duty-bound to correct (ibid.: 504–11). Furthermore, if phrenologists’ claim that mind is a function of brain is to be accepted, it is nevertheless the case that scientific thinkers do not have to accept their characterization of the brain as an object amenable to investigation by any human pathologist. Only comparative anatomists with access to a wide variety of difficult-to-obtain zoological specimens and preparations of nervous systems can pronounce on the proper function of specific cerebral structures.

This conviction that phrenologists had adopted an epistemologically naïve approach to human anatomy was shared by other writers concerned with articulating a zoology-informed conception of correlation between mind and brain. Not all physiological psychologists took such a critical stance regarding the doctrines of Combe and Spurzheim. Thomas Laycock corresponded frequently with Combe, in 1845 even going so far as to publish an exchange with him in The Lancet (Combe, Reid and Laycock, 1845). Similarly, though Herbert Spencer denounced the ‘unscientific reasonings of the phrenologists’, subsequent commentators have noted the impact of phrenology on his thought (Spencer, 1855, quoted in Cooter, 1984: 257). Whether they evaluated phrenology positively or not, however, it seemed clear to these figures that the moment for the doctrine in its ‘classic’ form had passed, and that different, seemingly more refined approaches were needed.

The contention that phrenology was an admirable but inadequate approach to psychology is typical of much physiological psychological writing, in that physiological psychologists based their claims on forms of evidence that the vast majority of readers would have had little or no means of evaluating for themselves. First, physiological experiments were both rare and morally suspect in Britain at this time; Magendie’s vivisectional approach was compared negatively with Charles Bell’s anatomy-based studies, which had reached similar conclusions (Cranefield, 1974); Marshall Hall’s experimental studies (addressed below) provoked intense opposition, with opponents citing the cruelty of vivisectional techniques (French, 1975: 18–23). Second, comparative studies of animal anatomy required the mobilization of significant resources (Yanni, 1999). Most readers had to take the zoological claims of physiological psychologists on trust, with texts such as Carpenter’s Principles acting as a benevolent means of ‘disseminating’ esoteric studies to their readers. Popular phrenological insistence on the identity of mind and brain was, increasingly, recast in physiological psychological texts as a significant but potentially deceptive contention that could be authoritatively evaluated and commented upon only by those who had already attained scientific respectability. Moving the criteria for psychological investigation away from relatively accessible human heads and towards difficult-to-obtain collections of zoological specimens and morally contentious experimental set-ups became a means by which physiological psychologists were able to render claims that had once seemed radical into respectable science. ²

Given the dual opposition that phrenology came to face from theology and physiological psychology, those who considered themselves as members of the respectable middle classes increasingly came to de-emphasize their one-time enthusiasm for such beliefs (Cooter, 1984: 256–71). In their place, a more ‘respectable’ science of mind and brain, reliant on the notion that it was only via the gaining of expertise in the nature of non-human life that one might know human nature, began to take shape.

The physiological psychological emphasis on epistemology

It is through the examination of disputes within physiological psychology that its specificities vis-à-vis other approaches are best brought out. One apparent difference between physiological psychology and the moral philosophic characterizations of mind that retained primacy in British psychological discourse throughout the century is the context in which the former was articulated. Whereas moral philosophy was almost invariably propounded by individuals trained in the classical subjects of rhetoric, grammar and logic, it would largely be graduates of the medical schools of Edinburgh and London who would elaborate the new physiological psychology in Britain. Yet, as Roger Smith notes, many of the concepts adopted or developed by physiological psychologists cannot be said to ‘belong to a history of philosophy or of psychology or of physiology, but [are rather the concern of]…a history in which these divisions themselves come into existence’ (R. Smith, 2011: 223). Only a small number of medical practitioners came to concern themselves with psychology during the period in question – usually those who sought to contribute to natural philosophy more broadly. In addition, the physiology that physiological psychologists appealed to retained an ambiguous relationship with medicine, drawing heavily on zoological studies in an attempt to construct a truly ‘scientific’ conception of the human body as it existed in a state of health rather than of disease. Those who initially promoted such zoology-oriented human physiology in Britain – figures such as William Lawrence and Robert Grant – were generally understood as standing against conventional medical and scientific knowledge (Desmond, 1989). Yet by the end of the 1840s, with phrenology increasingly sidelined, disagreements between physiological psychologists began to come to the fore. Carpenter and Laycock, for example, found themselves involved in a dispute that is particularly instructive regarding the above-mentioned physiological psychological emphasis on epistemology.

The two physiological authors had first met at University College London in either 1834 or 1835, both having attended Robert Grant’s courses on comparative anatomy and zoology there (Laycock to Combe, 1845; Laycock, 1855). That both figures came into contact with Grant’s zoology at this time is significant, in that their disagreement regarding the nature of the nervous system presents striking parallels with similar disputes that animated zoological discourse in Britain up until the 1850s (Desmond, 1989).

Carpenter closely followed the early-19^th-century trend in zoology towards comparative anatomical studies. His publications conceive of the nervous system in terms of a comparison of anatomical forms such as were collected in zoological museums of the period, charting the emergence of particular nerve structures at specific points in the animal series (e.g. Carpenter, 1839; Carpenter, 1842: 12–55). Of particular note for him are the elements of nervous anatomy that are not present or well-developed in ‘simpler’ animals.

Carpenter’s emphasis on anatomical comparison is accompanied by the adoption of a strictly hierarchical conception of mental function. Adhering to a broadly Aristotelian differentiation of psychological existence, his texts place particular emphasis on a functional distinction between three parts of the nervous system. Within the Aristotelian tradition, the human or ‘rational’ soul was marked by its dominion over two others: the ‘animal’ soul, which was responsible for such functions as the reception of sensation and the instigation of muscular movement, and the ‘vegetative’ soul, which fulfilled the basic or ‘nutritive’ functions of life (Dixon, 2003: 26–61).

Updating Aristotle for his 19^th-century readership, Carpenter cites the latest experimental and anatomical research. In a series of physiological experiments, Marshall Hall had seemingly confirmed experimentally that sensation could occur in accordance with the moral philosophic emphasis on reflex action as a non-conscious category of mental response (Leys, 1991; Clarke and Jacyna, 1987: 102–14). Bodily sensations had been described by such 18^th-century philosophers as Thomas Reid as having the potential to occur without the intervention of a conscious mind. This meant that the body might receive a sensation, assimilate it via the nerves, and respond, all without any involvement of the will or intellect (Dixon, 2003: 83–6). In Hall’s publications, and those of Carpenter following him, such perception is portrayed as dependent on reflex actions manifested by parts of the body that were nominally independent of a directing intellect, and which were characteristic of the experience of ‘lower’ animals (Carpenter, 1842: 127–8, 132–3, 228, for example). The nervous systems of ‘higher’ beings (especially humans) are on the other hand characterized by the anatomical predominance of regions identified as responsible for conscious, wilful intention. These functions are associated in these texts with the anatomical part that appears most developed in human anatomy – the cerebrum or outer covering of the brain (e.g. ibid.: 197–9). Finally, mediating between these functionally separate spheres is a third, functionally ambiguous region that Carpenter terms ‘sensori-motor’ (ibid.: 228–9). Located primarily in the cerebellum, this division of the nervous system operates as a halfway house between the reflex-manifesting action of the body, and a realm of pure rationality located in the cerebrum. As such, it constitutes the site of a set of psychological functions related to involuntary, instinctual passions or emotions, and semi-conscious, reflex-like muscular movements.

Laycock, meanwhile, placed greater faith in Grant’s somewhat idiosyncratic emphasis on a need to begin any analysis by addressing the simplest, microscopic elements of life (Sloan, 1985). Like Grant, his sympathies lay rather more towards the radical end of the spectrum of the 19^th-century reform movement than did Carpenter’s (Barfoot, 1995: 11–17). Following his zoological mentor, Laycock’s texts consistently emphasize what they portray as a pressing need to reconsider psychological life from the perspective of functions that are manifest in the most simple organic beings (Laycock, 1840; Combe, Reid and Laycock, 1845; Laycock, 1845).

Consequently, what Carpenter had characterized as ‘lower’ reflexes are elevated in Laycock’s texts to the status of a fundamental element of all nervous activity. Reflexes constitute a ‘substratum’ to which all accounts of mind must be made referable (Laycock, 1845). In contrast to then-prevalent conceptions of different parts of the nervous system as ‘possessing’ properties of unconsciousness, sensation, volition and so on, Laycock considers all such properties as depending upon psychologically independent reflex actions of the nerves.

In his psychology, Laycock conceives of the capacity for purposive action (or at least that which originates from organic bodies [Jacyna, 1981]) as gradually emerging in conjunction with the self-preserving activity of an increasingly complex order of organic forms. ‘Automatic’ or reflexive action is identified with the simplest microscopic ‘globules’ of life (Laycock, 1845: 309). This is followed by a progressive complication of function, passing through emotional states, and ending in complex forms of mental life such as will and volition (ibid.: 311). Crucially, the simplest psychological states constitute the conditions under which the more complex become possible (ibid.: 308). Hence intellect cannot be understood without a thorough appreciation of the causative role of instinct and emotion in the formation of the psychological states of all living entities.

The contrasts between these zoology-oriented conceptions of mind are clear. Carpenter emphasizes the anatomical differentiation of the nervous system into functionally distinct parts, tracing the emergence of these parts in terms of a ‘progression’ of life from simple to complex forms. Laycock insists that, fundamentally, the nervous system manifests only one kind of function: that of the reflex. To assign one or another of the ‘higher’ types of psychological life to a specific anatomical area is to mistake the admonitions of zoologists such as Grant that the most complex organic forms can be understood only in terms of a prior knowledge of their origins in the most simple.

At some point in 1849, Laycock submitted a journal article to Carpenter – then editor of the British and Foreign Medico-Chirurgical Review – that contradicted the latter’s anatomical stance. Though the original text is lost, it appears to have claimed that microscopic examination of the nervous system had revealed a direct connection between the cerebrum and the medulla oblongata (the lower part of the brain stem), which had been associated by Carpenter with intellectual and reflex-based functions respectively. The implication was that there is no intermediate ‘sensori-motor’ region of the brain that negotiates between a realm of pure intellect and bodily sensation. As Carpenter’s characterization of mind as a heirarchy of functional parts depended on the claim that all sensory nerves passed through such a region, Laycock’s commentary presented a direct challenge to his reputation as an authority on relations between mind and brain. Yet as editor, Carpenter enjoyed a privileged position regarding the expression of opinion on the matter. As his reply to Laycock explains:

I found myself obliged to omit parts of your article…as only embarrassing (in my apprehension) the discussion of the question of which you treat…What you call a nerve is a commissure, connecting the olfactory ganglia to the spinal axis (see Fisher). The corp[us] striata and thal optici [optic thalamus], moreover, are quite independent of the cerebrum as both Comp[arative] Anat[omy] and develop[men]t show…You must forgive me doctoring this Art[icle] a little, as it so closely trenches on my own subject. (Carpenter to Laycock, 1851[1850])

Carpenter eliminated those portions of Laycock’s article that did not agree with his own views. Worthy of greater note, however, is the way that he appeals to anatomical evidence in justification of his actions. Regardless of his position as editor, it is on comparative anatomical grounds that Laycock’s claims cannot be admitted.

Following this initial exchange, the correspondence becomes more mundane, and peters out entirely in 1852. To Carpenter it must have seemed that his appeal to comparative anatomy was successful, as the 4^th edition of his Principles of Human Physiology (1853) contains a note on Laycock’s work seeking to differentiate it from his own. Though Carpenter observes that Laycock had been the first author to apply the reflex function to the entire nervous system, he claims that he had not recognized ‘the essential distinction, both in their anatomical and physiological relations, between the Sensory Ganglia and the Cerebrum’ (Carpenter, 1853: 799–800, n.). He had failed, in Carpenter’s estimation, to ‘mark-out’ the distinction between the ‘sensori-motor’ or ‘consensual’ actions, which are the manifestation of the reflex power of the former [sensory ganglia], and the ‘ideo-motor’ [i.e. intellectual] actions which depend on the reflex action of the latter [cerebrum]’ (ibid.; original emphases). Carpenter’s text clearly marks out what he considers to be his original contribution to psychology – that there is an ontologically significant physiological difference between the reflexes that are associated with ‘lower’ functions such as movement, and those responsible for ‘higher’ functions such as intellect (ibid.: xi–xii). In claiming the originality of his doctrines in this way, Carpenter also claims the right to define what constitutes reflex or ‘automatic’ cerebral action – a phenomenon that in his (but not Laycock’s) view is distinct from the operation of the will and intellect in nervous life.

In 1855, Laycock responded to Carpenter’s claim. A long letter sent to both the aforementioned Noble and the geologist David Forbes sets out his objections. In it, Laycock’s chief concern is to portray Carpenter’s term ‘unconscious cerebration’ as entirely unnecessary, describing nothing more than his previously worked-out doctrine of reflex action of the cerebrum. This term operates in Laycock’s view as a means for Carpenter to avoid engagement with his own publications on the relations of physiological to psychological states:

As to that which he claims in the 4^th Ed[ition]…the distinction has been enumbrated [i.e. articulated] by me (in the true sense of the term) from the very first. The sensori-motor actions are as much reflex as the ideo-motor in my system, and are often equally independent of the will or consciousness. C[arpenter] has an anatomical scheme…the truth of which I very much doubt and which is I think in our present state of knowledge incapable of proof. (Laycock to Forbes, 1855; original emphasis)

Again, it is the status of anatomical evidence that is at issue here. As highlighted above, Laycock’s psychology relied to a far greater extent than did Carpenter’s on establishing the nature of microscopic organisms. By 1855, microscopy was beginning to enjoy a rather more respectable status within intellectual culture than it had during the early decades of the 19^th century (Jacyna, 2001). Carpenter’s statements had come under criticism from microscopists such as R. B. Todd and William Bowman, who had led him to reiterate his psychological categorization in rather different terms as early as 1850 (Todd and Bowman, 1835–59; Carpenter, 1850a). Laycock’s rejection of Carpenter’s ‘anatomical scheme’ reflects a sense of confidence in the epistemic status of his own claims. Critically, however, the dispute as a whole did not result in an irrevocable split between the two writers.

Deferring disagreements relating to nature of mind to disagreements relating to the epistemology of zoological science enabled the two physiological psychologists to maintain a sense of common purpose. Though Carpenter seeks to establish the originality of his physiological psychology, and Laycock denies the legitimacy of his claims, in a direct confrontation between the two the ontological status of specific nerves is not at issue. Rather, the commitment of both to establishing a science of mind and brain means that their disagreement revolves to a significant extent around deciding on the most appropriate means of conducting research on that part of the body.

In an immediate sense, Carpenter’s and Laycock’s agreement that nerves could be understood only in terms of zoological science contributed to their ability to maintain a collaborative, if at times strained, working relationship (see, for example, Carpenter to Laycock, 1855 and Carpenter to Laycock, 1873). Questioning the most appropriate means of investigating nerves rather than specific claims regarding the nature of mind meant that disagreements regarding the latter could (ideally) be resolved in the academic arena of zoological-physiological investigation, through the evaluation of the legitimacy of differing approaches to observation. Physiological psychologists participated in (though of course by no means defined) the constitution of a scientific discourse in which ontological questions regarding what nature was were increasingly coming to be addressed via epistemological questions regarding how nature should be studied. Those psychologists committed to the articulation of a conception of mind as an embodied phenomenon would from this point on place increasing emphasis on the evaluation of different techniques and practices of investigation. For example, later in the 19^th century, microscopic and comparative anatomical evidence came to be sidelined in favour of a vivisection-centred approach. John Burdon Sanderson would insist in the Handbook for the Physiological Laboratory (1873) that, above all else, physiology ‘belonged in the laboratory’ (Sanderson, 1873: vii) – a statement that 20^th-century behaviourists would elaborate into something akin to psychological dogma (Mills, 1998).

The 19^th-century association of mind with a zoologically informed conception of nervous life had effects that extended beyond the immediate question of ontology, and into practice-oriented questions regarding the kinds of equipment that might be necessary for the conduct of psychological investigation. The moral philosophers of the 18^th century had understood the conduct of philosophy in terms of a following of the rules of rational thought. To the extent that physiological psychology deferred not to individuals’ capacity for reason, but rather to their ability to evaluate and utilize particular kinds of observational equipment appropriately and effectively, it constituted a significant break with prior modes of enquiry regarding mind. Though this break had seemingly little immediate impact on psychological thought, it nevertheless did play a role in the constitution of an experimental ideal of scientific endeavour.

Physiological psychological rhetoric and laboratory science

Perhaps the most pertinent example of the way in which physiological psychology actively participated in the constitution of a new conception of scientific conduct during the latter decades of the 19^th century concerns the institutionalization of laboratories. The claims of physiological psychologists accorded particularly well with the beliefs of those seeking a general reorganization of scientific practice around buildings devoted to experimentation. Physiological psychology-derived rhetoric came to be deployed by experimentalists as a tool with which they sought to attract resources. Specifically, the articulation by physiological psychologists of a conception of intellectual activity as a type of bodily ‘work’ became a cornerstone of a more general call to establish laboratories in all of Britain’s universities and scientific institutions.

It is well known that the early-19^th-century body was distinguished from mind in terms of its capacity for work. The point would seem moot, were it not for Rabinbach’s and others’ demonstration of the ways in which the question of bodily work came under close scrutiny during the middle decades of the 19^th century (Rabinbach, 1990; Kremer, 1984). Prior to this time, the assumption that the body was a non-intellectual working object had remained the largely unspoken counterpart of the moral philosophic concern with mind as an entity abstracted from the physical world (Barnes and Shapin, 1976). Mid-to-late-19^th-century physiological psychologists challenged this differentiation by emphasizing the dependence of mind on bodily activity, and the interchangeability of mental and physical work.

The key intellectual context within which this shift occurred was the development of the science of energy. That the emergence of energy science was closely related to a growing feeling that natural philosophy should be conducted as above all an ‘experimental’ endeavour is also well known (C. Smith, 1998). Yet though Hall (1979) and R. Smith (1970) have highlighted the close connections that existed between physiological psychology and the emergence of a science of energy, less attention has been paid to ways in which these connections related to the simultaneous emergence of an ideal of science centred on the conduction of experiments in institutionalized laboratories.

19^th-century Britons, like their continental counterparts, were deeply concerned with relations between nature and the industrial processes that (it was generally presumed) would harness nature’s potential to human ends. The possibility of converting natural power into industrial production – or organic ‘energy’ into human ‘work’ – became a significant preoccupation of mid-to-late-19^th-century physiological science (Dierig, 2003; Rabinbach, 1990: esp. 45–68 and 120–45). Along with physicists and chemists, chemically oriented physiologists participated in the articulation of a conception of nature as first and foremost a transaction between different kinds of ‘force’, ‘power’, or ‘energy’ (E. Smith and Milner, 1862; Frankland, 1866; Playfair, 1865).

In their adoption of the notion that nature fundamentally constitutes an exchange of energies, powers, or forces, physiological psychological authors found further justification for their self-appointment as authorities on the nature of mind. A Philosophical Transactions article of Carpenter’s from 1850 exemplifies the predominant physiological psychological approach to force and energy. The article is primarily concerned with delineating ways in which cells convert ‘vital power’ into organic matter and heat. But it also posits the existence of another distinct power which, it suggests, is possessed by nerves alone: ‘related on the one hand to the conscious mind, to which it communicates impressions derived from the external world’, it is also ‘related, in a very remarkable manner, to the vital endowments of the organism in general…and particularly to the contractile tissues’ (Carpenter, 1850b: 736). The article draws a strong contrast between the mode of nervous action and that of other bodily processes, thereby suggesting that different types of (still interchangeable) forces could be assigned to each. This notion of an interchange of forces within the body was critical to mid-to-late-19^th-century conceptions of mind as a labouring entity.

Such rhetoric encouraged physiologists to speculate on relations between working bodies and thinking nerves, thereby incorporating a notion of mental labour into their claims. For example, the Scottish chemist, parliamentarian and agitator for educational reform Lyon Playfair (who would later write a treatise on bodily energy consumption) deployed physiological psychological claims to great effect in his diagnosis of what he saw as the disappointing performance of British industry at the Great Exhibition:

Labour…is of two kinds…muscular and nervous…The fact is every day more apparent, that mere muscular labour, in the present state of the world, is little better than raw material, and that both are sinking in value as elements of production, while nervous or intellectual labour is constantly rising. The whole of industrial competition is now resolved into a struggle to obtain a maximum effect by a minimum expenditure of power. But this power is derived from natural forces, and not from brute strength: mental labour has engrafted itself upon muscular effort, and, by a healthy growth, has reduced the size and relative force of the latter. (Playfair, 1852: 5)

The 1860s witnessed a slew of publications addressing the place of force and power in mental life. Laycock’s Mind and Brain (1860), J. D. Morell’s An Introduction to Mental Philosophy (1862), Spencer’s First Principles (2nd edn 1867) and Henry Maudsley’s The Physiology and Pathology of Mind (1867) all addressed the ‘correlation’ of forces or powers in the body.

Another key feature of this burgeoning literature was its emphasis on the non-nervous body as an active participant in the constitution of thought. This was achieved by according muscles an originary role in the act of perception. Roger Smith notes that such philosophers as George Berkeley and Thomas Brown had portrayed the organs of sense (and especially touch) as having an active role in perception prior to this time. Similarly, French ideologues placed particular emphasis on touch in the constitution of mind during the 1790s (R. Smith, 2011: 223–32). Nevertheless, these conceptions of bodily activity tended to privilege mind (or will) as the active agent of muscular movement. The mind or will directed muscles, which in turn either directed other sense-organs, or, when impeded by an outside force, themselves acted as a sensory mechanism, engendering a feeling of ‘resistance’ in the perceiver (ibid.: 228–32). Drawing on claims by such figures as Destut de Tracy and Xavier Bichat, British physiological psychologists emphasized the active and independent role of muscles in perception, and articulated a conception of muscular movement as independent of, and even ontologically prior to, intellect.

The most emphatic theorist in this regard was the Scottish psychologist and educational reformer, Alexander Bain. One of the first professors of English in Britain, Bain was deeply committed to the consideration of sensation in terms of a physiology informed by the latest zoological science (Flesher, 1986: 215–44; R. Smith, 2011: 235–7). His 1855 The Senses and the Intellect marks the beginning of a sustained consideration of muscles as active and independent participants in the constitution of mind. Its introduction proclaims that Bain had ‘thought proper to assign to Movement and the feelings of Movement a position preceding the Sensations of the senses; and…endeavoured to prove that the exercise of active energy…is a primary fact of our constitution’ (Bain, 1864[1855]: vii). As infants develop, they begin to control the spontaneous actions engendered by the release of energy by associating some of those actions with specific sensations. His later The Emotions and the Will (Bain, 1859) elaborates on this notion, presenting the sense of self as emerging as a result of interaction between the tendency of bodies to expend muscular energy, and the environments in which they act (see also Flesher, 1986: 245–73). The development of particular tendencies within the nervous system depends on the repeated spontaneous release of non-nervous bodily energy in a specific direction: ‘Spontaneous movements are without doubt confirmed by repetition, and thereby made to recur more readily in the future. Any movement struck out by central energy leaves as it were a track behind, and a less amount of nervous impulse will be required to set it on a second time’ (Bain, 1864[1855]: 334). As it is required for nervous development, the action of the working body constitutes a condition of possibility for thought and memory: ‘Actions, Sensations, and States of Feeling tend to grow together, or cohere in such a way that when any one of them is afterwards presented to the mind, the others are apt to be brought up in [an] idea’ (ibid.: 332).

Furthermore, in conceiving of the body as a site in which energy or power is constantly being exchanged between muscles and nerves, physiological psychologists portrayed the bodily activity of experimental practice as an ideal means of cultivating mind. As an 1848 text of Bain’s comments:

… in chemistry…there is a discipline more than merely mathematical. The laboratory operations of testing and analysis, in which every blunder recoils upon the operator, and where his knowledge, ingenuity and watchfulness are incessantly on the stretch, may be strongly recommended as a discipline of the reasoning and judging faculties; and in many instances it would probably be the best training that could be chosen. (Bain, 1848: 455)

Such statements found an increasingly broad readership from the 1850s on. Herbert Spencer’s widely read Education: Intellectual, Moral and Physical (1861) staunchly advocates a need for children to engage actively with nature, rather than be taught the nature of things via lectures or static ‘object lessons’. By the late 1860s, even such comparatively conservative authors as the grammar-school head and educationalist Robert Hebert Quick were citing the need to attend to active, ‘spontaneous’ modes of learning above the ‘supplementary’ function of books (Quick, 1868: 249–50).

It should be noted that many of the principal proponents of physiological psychology were not themselves experimental practitioners – Spencer considered himself first and foremost a ‘synthesizer’ of others’ work; Bain’s interests were primarily linguistic. Nevertheless, the discourse of physiological psychology played a critical role in the establishment of an assumption that experimental activity was fundamental to ‘scientific’ learning. Moreover, physiological psychologists were themselves active in the move to instantiate laboratories in Britain’s universities. Carpenter, who had by the 1870s attained the position of registrar of the University of London, played a prominent role in the foundation of a science faculty at University College London, which prided itself on its newly founded laboratories (Harte and North, 2004: 80–95). Carpenter and Playfair promoted experimental learning in their roles as key witnesses to the 1867–8 governmental committee on ‘Instruction in Theoretical and Applied Science’, a significant motivation for the British government’s move to fund laboratories from this time (Anon., 1970[1867–8]: esp. 58, 107–13). Laycock played a key role in the training of such now-lauded experimentalists as the founders of Brain, John Hughlings Jackson and James Crichton-Brown, as well as David Ferrier (whom Bain also taught). Bain himself was a staunch advocate of experimental science at the University of Aberdeen, successfully campaigning in 1889 for the university to confer degrees in scientific fields (Simpson, 1963: 64–5).

At the same time, the physiological psychological conception of mental activity as a kind of ‘work’ became a means by which experimental practitioners less concerned with the consideration of mind in the abstract sought to portray their activities as economically relevant. Though Thomas Henry Huxley declared himself undecided on the question of the association of mind and brain, he nevertheless insisted that all workers, whether ‘manual’ or ‘intellectual’, could and should unite around the laboratory as a totem of technical education (White, 2003: 148–55). John Tyndall insisted on the capacity of experiment to turn science to ‘practical account’ (DeYoung, 2011: 131–70). For such advocates as Huxley, Tyndall, Spencer and Bain, even subjects conventionally understood as outside the purview of natural philosophic enquiry such as art and literature would benefit from the adoption of an experimental approach (e.g. Bain, 1868).

By the 1870s, physiological psychological rhetoric concerning intellectual work had become an important tool with which even those with little or no explicit interest in psychology sought to elicit support and sponsorship for the establishment of institutions devoted to experimental practice. To give one fairly typical example, in an opening address to the newly constituted Faculty of Science at University College London the professor of chemistry Alexander William Williamson drew a direct correlation between the establishment of laboratories and the cultivation of British industry:

… the mental qualifications which enable a man of business to contribute to progress in the particular industrial operations which he conducts, may be described by one word:- they are the qualifications of an experimentalist.

The introduction of any change in an industrial system is an experiment; and whoever manages it ought to know that it is one, and to conduct it in such a manner as to make it a true and good experiment. (Williamson, 1870: 21)

Between 1860 and 1880, the number of laboratories attached to Britain’s academic institutions mushroomed, along with the rapid expansion of the university sector more generally. Calls for the foundation of institutions in which students of botany might themselves ‘handle the plants and dissect the flowers’ (Huxley, 1893–4[1860]), in which students of chemistry would be ‘taught to observe for themselves’ (Frankland, 1875), and in which those of physiology would be introduced to the intricacies of vivisectional practice (Sanderson, 1873) multiplied from the late 1860s (Cardwell, 1972[1957]: 125–6, 130–1). That universities and scientific institutions came to see laboratories as a key means of gaining and/or maintaining intellectual and economic credence was in no small part due to the emergence of a zoology-informed conception of learning as a physiological process that privileged bodily interaction with observational equipment over the reading of texts or memorizing of speeches.

Conclusion

The principal relevance that physiological psychology had to the sciences of the late 19^th century regarded attitudes towards investigation, rather than claims being made in particular intellectual fields. As this article has argued, in Britain at least (for comparison with the contemporary situation in Germany see Schmidgen, 2004), mid-19^th-century physiological psychological conceptions of knowledge production privileged bodily movement and the use of experimental equipment over textual description. This emphasis accorded well with the concerns of British experimental practitioners, who appealed to physiological psychology-derived characterizations of mental activity as a kind of labour in their efforts to persuade policy-makers of the economic efficacy of laboratory science. Physiological psychology as an intellectual movement participated fully in (though, it should be emphasized, by no means directed) the articulation of a notion of science as an activity most effectively conducted by professionals in laboratories based in higher education institutions. Though the intellectual movement had all but disappeared by the 1890s, it left its mark in that it would become increasingly conventional to view producers of (scientific) knowledge as a kind of labourer during the late 19^th and early 20^th centuries.

The relation between the physiological psychology of 19^th-century Britain and the neurology of the present day is not of course entirely straightforward. As the proposed ‘neuro-’ moniker for history indicates, the institutional reach and influence of neurology is far wider and deeper than that of its 19^th-century cousin. Similarly, present-day neurology addresses a far greater range of biological entities, and seeks to explain a far broader range of pathological states, than could have been contemplated by the physiological psychologists (Fuller et al., 2014). Yet it is also the case that many of the tropes of physiological psychology highlighted here – concern with relations between nerves and the rest of the body, recourse to questions of epistemology rather than ontology during disagreements, a general assumption that the study of mind and brain is not possible without the possession of considerable research resources and equipment – remain relevant within currently active departments, disciplines and groups dedicated to neurological research.

As for neuro-history then, the constitution of this emergent historiographic trend is as yet uncertain. The foregoing suggests that in addition to the already-underway move to revise historical narrative in the light of the findings of current neurological science, a fully fledged neuro-history is also likely to raise questions relating to practices of historical writing and research. On this reading, the neuro-turn would herald the formulation of an historical epistemology centred on an ideal of experimentation (potentially similar to that articulated in Sibum, 2000). Such an eventuality would contrast with current approaches, which tend towards the natural history-like description of source material, or its analysis and subsequent synthesis into narrative (for differentiation between these categories see Pickstone, 2000: esp. 10–15).

The desirability or otherwise of such a neuro-history, of course, is a rather different question. What does appear clear is that the emergence of an intellectual climate that is by and large defined by the concerns of science- rather than humanities-oriented disciplines has fostered deep anxiety regarding the continued viability of critically engaged historical scholarship (Cooter, 2014). The increasing ubiquity of neurological conceptions of existence, regardless of their ongoing ontological critique, indicates that any critical apprehension of such conceptions requires payment of as careful attention to epistemological questions relating to humanities scholarship (as raised, for example, in Hayles, 2005) as has hitherto been accorded the claims of philosophers and nerve scientists regarding the nature of mind.