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Nature, Mind and Body
in the Age of Mechanism
A dissertation submitted in fulfillment of the requirements
for the degree of Doctor of Philosophy
University of London
This thesis explores the ways in which the mind-body relationship was problematized after Descartes, in the context of the scientific revolution in the second half of the seventeenth century, both in France and in England. It is an attempt to historicize ongoing debates within the cognitive sciences and the philosophy of mind about the problem of consciousness. By reconstructing a history of the status of the self-aware, human mind through the history of scientific explanation, I address the question of whether or not a complete, scientific explanation of higher consciousness is possible.
Adopting a conceptual, rather than chronological framework, I concentrate on figures who played a role in the scientific, theological and philosophical debates of their day, rather than on the subjects studied in modern philosophy curricula, although Descartes, Locke and Malebranche are present throughout. Part I focuses mainly on post-Cartesian views on dualism. Part II relates these theoretical debates to discussions about the nature of scientific enquiry. The thesis begins with Fellows of the Royal Society, including William Holder and George Dalgarno, who discussed the possibility of devising a language for the deaf, as well as the nature of language, ideas and perception. Orthodox followers and later interpreters of Descartes like Gérauld de Cordemoy, François Fenelon and Louis de La Forge also wrote about these issues. Debates over the Cartesian ‘beast-machine’ thesis and over definitions of reason and instinct, are considered next, by looking at the works of Ignace-Gaston Pardies, Antoine Dilly and Pierre Bayle. These discussions were a manifestation of the need to define human nature apart from its physical embodiment. Part II begins with a consideration of the various ways that sceptical traditions informed programmes of scientific enquiry on both sides of the Channel, through the writings of Joseph Glanvill and Bernard de Fontenelle, among others. Arguments about teleology and about the relation between anatomical form and physiological function by thinkers and natural philosophers such as Robert Boyle, Nicolaus Steno and Thomas Willis are treated in the next chapter. These enquiries prepare the ground for the final chapter, which considers texts by physicians and anatomists, including Claude Perrault and Guillaume Lamy, on the physiology of the ‘corporeal soul’.
A note on the text 7
I. Signs of mind and the souls of beasts 29
1. Deafness, ideas and the language of thought 40
2. From other minds to animal bodies 76
3. The beast-machine controversy:
reason, instinct and the causality of motion 107
II. Teleology, science and scepticism 131
1. Other worlds: the science of knowledge 140
2. Understanding function: the organs of cognition 165
in animal and man
3. From sense to soul: God, reason and human will 201
This project, like many PhD dissertations, has taken a fairly long time to complete. It has been a privilege to be able to spend these years on research, thinking and writing, with few cares in the world apart from the joys and anxieties usually associated with the contemplative life. For better or worse, this is a doctorate I can claim to have needed to write, and I am immensely grateful to all those who have supported me in my wish to pursue this line of enquiry, and who have believed in its potential interest.
The Warburg Institute has been a unique institutional home and a haven of old scholarly values. The topic of the dissertation was conceived here, where the commitment to interdisciplinarity allows for great freedom of thought. Jill Kraye, who has guided this project at the Warburg, is bound to be one of the most available, supportive and dedicated supervisors anywhere. The thesis, such as it is, would not have come into existence without her presence; nor would it have found its shape without her editorial rigour, her intellectual discipline, her measured but constant encouragement, and her interest in helping me find a methodology suitable for the development of an argument more philosophical than historical. Most importantly, she has taught me how to temper my inordinate flights into abstraction, with a dose of the historian’s sobriety here and a dose of passion for clear thinking there. Charles Hope is another member of the Warburg staff to have witnessed the work’s progression from inception to completion, reading chapters as they slowly poured out, with sympathy, interest and a welcome eye for incoherences.
Outside the Warburg, David Papineau generously read the text as it took shape, providing me at regular intervals with necessary philosophical comments and questions on some crucial points. A meeting with Simon Schaffer at the very beginning provided enough material for the next years; Rivka Feldhay’s interest early on was encouraging. Alexander Goldbloom helped me on many occasions from his base at the Wellcome Institute. Talks with Kristine Haugen have been illuminating. Thanks to Georges Rey for a provocative conversation, to Kenan Malik for a provocative argument and to Luca Turin for a provocative remark. I am grateful to Richard Serjeantson, who read and annotated the chapters on animal minds with care and interest. Daniele Derossi has taught me much on Renaissance anatomy. Many thanks to Gloria Origgi for some especially pointed and clarifying comments she made on a few sections of the thesis; to Pia Pera and Adam Freudenheim for reading the introduction; and to Roberto Casati for helpful remarks early on. I am also grateful to David Goodhart and Prospect Magazine for providing me with a ‘real world’ base and to Edmund Fawcett for lengthy lunches and a writing outlet.
Daily interaction with members of the Warburg, whether staff or students, is bound to have left much more than an academic mark on life after the PhD. François Quiviger’s friendship over the years extends far beyond the Institute; his insights and our exchanges on topics we both have battled with have been formative in countless ways. Surrounded by art historians, I have not had time to miss the images absent from this thesis; but I have learned how to begin understanding them better. Ending the day in the photographic collection invariably revived the mind and gaze; thanks to Paul Taylor, Mariana Giovino and Rembrandt Duits for their catching enthusiasm. My sense of belonging to a wonderful community was due in large measure to the affection of Liz McGrath and that of Ruth and Nicolai Rubinstein, as well as to Nico Mann, who, as Director of the Institute, contributed much to this sense of belonging. I thank him for giving me the opportunity to spend these marvelous years here. Working in the bright second-floor student room of the Warburg building, overlooking the squares of Bloomsbury, has been a remarkably joyful experience; the company of Annie Giletti, Marika Leino, David Porreca and Alessandro Scafi over the last year of work has sweetened the rush to completion. Daniel Andersson’s many appearances were energizing; I thank him for comments he made on the subject of this thesis and for bibliographical advice. Guido Rebecchini was a supportive accomplice earlier on, as was Julie Boch, who sojourned further along the corridor and shared her insights on Enlightenment literary history.
The process of conceiving and writing this doctorate has been marked by numerous friendships and conditioned by timely, crucial meetings. I can only mention a few here. It is fair to say that the seeds of the project were sown when I first met Israel Rosenfield and Catherine Temerson some eight years ago - before I had even decided to pursue postgraduate studies - at the end of a formative internship at the New York Review of Books. While there, I had already begun developing an interest in the history and philosophy of the mind sciences; but it was fed over the following years by many conversations with Israel, by his scepticism about our capacity to understand minds and brains and his knowledge of the role of history in shaping our beliefs about them.
More people than I can name here helped the thesis grow, directly or indirectly. I am grateful to John Armstrong, Guido Branca, Robyn Davidson, Anthony Dworkin, Edmund Fawcett, Adam Freudenheim, Eva Hoffman, Toby Mundy and Turi Munthe for stimulating talks and for their interest; to Jeff Spier and Monique Kornell, Katia Basili, Mira Margalit, Pia Pera, Benedetta Tournon, Ute Wartenberg and Margrit Wiesendanger, present even from abroad; to my upstairs neighbour Larry Dreyfus for practicing his viola da gamba at home; to Daniele and Susanna Derossi, for their generosity. I have relied much on Alain de Botton’s insightfulness. Ian Buruma has influenced me over the years more than he might imagine. I met Claudia La Malfa in the second-floor student room at the Warburg, and she knows what her presence means. Miriam Rothschild’s passion for science has fanned my curiosity for well over a decade; week-end long conversations and her encouragement have been a great source of inspiration. Laura Bossi, whose thinking is close in spirit to mine, has also been encouraging in a most positive way. Finally, another serendipitous encounter occurred just over a year ago, with Gloria Origgi and Dan Sperber; in many ways, meeting them has been like finding another home.
I was told that the last year would be hell; but it was not. It is most probably thanks to Enrico Galliani that I have been able to hold on to sanity and finish the thesis at last; he knows how grateful I am for his patience, criticism and loving support. My sister Alba Branca and her family have more than tolerated me throughout these doctoral years and have given me sustenance, joy and encouragement. But without my parents, I simply would not have begun at all. They have believed in it from the start and have been interested readers, attentive listeners, inspiring and constantly present. There are no words to thank them for everything they have always provided in all ways, material, emotional, moral, intellectual. It is to my parents, Anne and Avigdor Arikha, that I dedicate this thesis.
A note on the text
1. Subject-matter, methodology and purpose
This dissertation presents a history of the mind-body problem in the context of the new corpuscularian philosophies of nature which characterized the Scientific Revolution. It concentrates on the period immediately after Descartes’s death in 1650 until the late 1690s, just before the fully fledged establishment in France and England of Enlightenment society, culture, science and philosophy. Its main concern is to historicize some key concepts in current discussions about the mind.
The mind-body problem as it stands today is the outcome of a puzzlement growing out of the increasing sophistication, precision and refinement with which we are able to comprehend the nature of matter, of our bodies and of our brains. It addresses the question of how a precise understanding of matter can yield, or correspond to, a precise understanding of what it is to be human - to have consciousness, subjectivity, a self, memory, a mind.1 But apart from representing a battle on the ground of science’s new capacity to identify, gather and interpret data about our brain and about our mental life, the mind-body problem constitutes one of the great chapters in the history of ideas, because it sits at the confluence of scientific and humanistic pursuits. In its earlier guise - from Plato and Aristotle on - this enduring question centred on exploring what sort of relation could possibly exist between soul and body (rather than between mind and brain), given that we were both embodied and capable of thought, positioned somewhere between beasts and angels. But the idea that matter alone could be amenable to scientific scrutiny and that it was entirely separate from the self-aware, conscious, immaterial mind is known to have begun life in its modern form with Descartes. He split apart matter and mind, forcing human higher cognition into a realm available only to individual introspection. The philosophical and theological debates which followed among natural philosophers and men of letters alike in the mid- and late- seventeenth-century were momentous, and the issues they engaged with are ones we still consider unresolved.
It is these debates, in the wake of Descartes’s hypothesis of mind-body dualism, which I shall attempt to reconstruct, moving between England and France and often comparing the discussions in each country. If these debates can help us put into historical, contingent context our own perplexity about the power of scientific enquiry to shed light on human nature, it is because they took place at a time when the disciplinary boundaries which prevail today in the academic world did not yet exist. These disciplinary boundaries ensure that the plentiful scholarship on the history of that period’s science and philosophy often fails to inform the prodigiously rich and varied work that has been emerging in the new fields which constitute the cognitive sciences, the neurosciences and the philosophy of mind.2 Standing at a juncture between the histories of science, medicine and psychology, the history of philosophy, epistemology, and the philosophy of mind itself, I do not claim to contribute new material to either of these fields, nor to offer a synthesis of the existing scholarship growing every day within them. What I have tried to do, instead, is to transcend disciplinary and methodological barriers that did not exist in the period covered here; failing to do so would be, in effect, to distort from the outset the nature of the mind-body problem at that time.
Analysing what this ‘problem’ was about during the period between 1650 and the 1690s entails studying a variety of texts which participated in configuring the cultural debates around the questions inherent in the very plausibility of positing an hypothesis such as Cartesian mind-body dualism, that is, the strict distinction between the body, defined as res extensa, and the soul, defined as res cogitans. These texts concern - in order of appearance in the dissertation - effects of sense-impairment on experience and thought; language use and language acquisition; learning and education; animal minds and animal souls; definitions of scientific observation and scepticism; teleology and functionalism; the modalities of sense-perception and second-order cognition. Research into all of these aspects of mental activity would be pursued in the eighteenth century, a period when materialist creeds became consolidated and atheism more widespread; and in the nineteenth century it would lead to the first attempts at a scientifically modern neurology. These same issues continue to be investigated today by cognitive scientists, whose assumptions about the nature of the mind are, however, informed by research into a biological universe that was unknown, and arguably inconceivable, until recently, whose relevant history is not entirely contained within the historiography of biological sciences and medicine.
What made it impossible for the mind’s contents to be a concern of biology before the modern era is one concrete historical question that this dissertation seeks to answer.3 A thorough treatment of this question would obviously require an in-depth study of the decisive events in the history of eighteenth- and nineteenth-century science, medicine and philosophy. The story told here is concerned instead with the background to these developments. Criss-crossing disciplines rather than centuries, I attempt to unravel the relation that late seventeenth-century empirical observations of the mind’s workings bore to the period’s philosophical, theological and ethical concerns. Such an approach should help us understand the nature of the assumptions underlying early modern, foundational philosophical enquiries which, eventually, made it possible to devise questions and methods for the scientific investigation of cognition through analysis of the brain and nervous system, as well as through the study of the psyche and the observation of behaviour. Nevertheless, our desire to comprehend the mind-body relation is still not wholly satisfied by the increasing ability of the neurosciences and cognitive psychology to tell us what we are made of.4 It is hard to interpret the data, partly because we do not know exactly what data to look for and partly because the bounds within which science can explain us to ourselves are not fixed.
The approach here is interdisciplinary insofar as it is based on the close reading of texts with an eye to both the early modern intellectual context and the modern issues of epistemology on which they shed light. In adopting this methodology, I do not claim affiliation to any particular school of thought. What has guided me is an interest in historicizing the scientific mind, in the belief that doing so would give us a perspective on what is involved in relying, or not relying, on scientific explanation as a means of understanding ourselves, our lives, our bodies and our world. This is why I have paid attention to the reasons for holding beliefs about the nature of mind and matter, rather than to the internal coherence of these beliefs, which usually preoccupies those who study the history of philosophy.5 In no way, however, does this constitute an endorsement of an anti-realist or subjectivist position with regard to science;6 nor is it intended as a defence of ‘alternatives’ to properly scientific explanation, such as vitalism, the belief in occult forces and so on. Nevertheless, the notable popularity of extreme relativism,7 on the one hand, and of ‘alternatives’ to mainstream science, on the other, points to the need to examine what relation mind and reason bore to body and emotion at a point in time which precedes the entrenchment of positivism in mainstream scientific theory and practice.8
2. Philosophical context
The advent of the ‘new philosophies’ of mechanism and atomism during the century preceding the Enlightenment - roughly, from Galileo and Descartes to Newton and Locke - shattered the harmony between man and nature which had been imposed on the practice of natural philosophy in the Renaissance by the almost exclusive reliance on traditional, Aristotelian and scholastic texts. It thus provoked major changes in the understanding of the nature of matter and bodies, together with elaborate discussions about the status of the new physics and about physical explanation generally, about causality and forces in nature, and about the limits of reason. These discussions can be illuminating for us, as can be the humanist scepticism which informed the best writings of the time. There was a pressing need then to redefine, in order to preserve, the privileged status of human beings in the realm of nature, as creatures of God endowed with an immortal soul and with free will. At the forefront of the debates about and within the new mechanistic and atomistic systems was the profound anxiety about their consequences for the non-material human soul. In this way, epistemology (questions about what constituted human knowledge) was inseparable from both psychology (questions about the human passions and their relationship to reason) and metaphysics (questions about the place of humans and of the human soul in the God-created universe).
Having separated the soul from the body, Descartes failed to convince many of his contemporaries of the viability of the resulting physical organism, which led him to identify beasts with automata. Today’s ‘zombies’ are not dissimilar to Descartes’s ‘automaton’ and ‘beast-machine’: they are creatures spawned by a thought-experiment frequently used by modern philosophers of mind to imagine how an artificially contrived organism mirrored on ourselves but deprived of ‘consciousness’ would function. Descartes’s own thought-experiment served the opposite goal, since it was supposed to prove the immateriality of mind rather than show how hard it was to prove it; but it provoked fear in his time that a ‘man-machine’ might eventually be conjured up, as indeed Julien Offray de La Mettrie would do a century later, in L’homme-machine.9 Furthermore, our questions about how an organic substance could ever ‘produce’ consciousness and reason are not far removed from the earlier worries about the place of the soul within the purely mechanical Cartesian organism. Given that we think of higher consciousness as unique to humans, our puzzlement about its status within our mortal frame echoes, too, the need of seventeenth-century religious thinkers to preserve the immortal ‘rational soul’ which humans alone possessed and which marked the difference between man and beast.
Although the theological concern with the immortality of the human soul is no longer a defining element in Western culture, the evident wedge between man and animal ensures the persistence of human exceptionalism.10 It is true that, ever since Darwin, we do not dare to think of nature in anthropocentrically hierarchical terms, with humans at the top. It is now widely accepted that consciousness must be embedded in cognitive processes we share with other creatures: even language, it seems, began with physical gesture.11 But the interest today in speculating about the nature of animal minds12 does have an historical counterpoint in the obsessive need of earlier thinkers to draw the - theologically necessary - boundaries between animal and man by establishing what kind of soul God could possibly have granted to creatures seemingly deprived of higher cognition and language. There was a metaphysical dimension to debates about how to distinguish deliberative reason and acquired knowledge from natural instinct, just as there is today a philosophical dimension to debates in the cognitive sciences about the nature of mental representations and of their relationship to our distinctly human linguistic capacity.13 These present-day debates include questions about the nature of what is understood as ‘higher order thought’, or ‘metarepresentational’ consciousness,14 a concept which appears to be parallel to that of the earlier rational soul. They also include questions about the nature and significance of our capacity to know ‘other minds’, a problem posed with great force from Descartes onwards and which formed one aspect of the deliberations about animal minds.15 These discussions now reflect wider, topical concerns - at times ideologically inflected - about how to define ‘innate’ and ‘acquired’ knowledge, which are themselves connected to anthropologically inflected questions regarding the ways in which we define the relation of ‘nature’ to ‘culture’.16
3. Conceptual framework
Although I have been aware throughout the writing of this dissertation that anachronistic fallacies lay just around the corner, I have strived to remain on a straight line in the telling of a story that in itself is not temporally linear. Its structure is based on a number of assumptions that arise from the course of ongoing discussions about the nature of the human and the animal mind and about the related difficulties inherent in defining the self-conscious, human person as an individual member of a species. The dissertation is thus conceptually, rather than chronologically driven, in that its protagonist is a concept (and anti-hero of sorts): the ‘explanatory gap’,17 inherent, as some argue today, in physicalist explanations of consciousness. Such arguments state that since human consciousness is irreducibly subjective and immaterial in phenomenal terms, its depiction in physical and naturalistic terms seems to leave out the very element such an account seeks to embrace, the ‘what-it-is-like-ness’ of subjective experience, the so-called ‘qualia’ that make it up. Seventeenth-century discussions of the mind-body problem in the context of Cartesian dualism reveal an equivalent explanatory gap. Unnamed until the twentieth century, it is nevertheless at the heart of this discussion simply because it determines the very structure of the mind-body problem in its post-Cartesian guise.
I take the explanatory gap to designate primarily the sense that any theory of cognition based on neurological or generally physical explanations does not constitute an answer to the question of how it is that we are what we are, in the terms in which we experience, and think ourselves to be what we are, that is, individuals endowed with consciousness. This was a truism at a time when the concept of ‘soul’ had potency. Today, given the available tools of scientific interpretation, together with the scientific ineffectiveness of this earlier concept of ‘soul’, there remains a great difficulty in explaining what sort of relation consciousness, invisible as it is, bears to the visible white and grey matter with which it is obviously associated, how brain events correspond to mental events, which is the cause of which, and what the modality is of this correspondence. ‘Consciousness’ as such only became a subject-matter by default, out of the sense, which arose in the wake of the short-lived behaviourist trend of the 1960s, that models of the mind based on neuroscientific theories left it out of the picture. I assume from the outset that the existence of this metarepresentational capacity as a central aspect of our embodied, evolved and mutually interacting selves must be taken into account within any theory of the human mind for such a theory to be plausible.18 This is a relatively new notion, although by now monism does seem to be slowly replacing the Cartesian dualism within which the explanatory roles of modern philosophy and modern science, respectively, were defined.19
The issue of whether or not the explanatory gap can be closed has been discussed abundantly in recent years. My concern, however, is not to treat the explanatory gap within a technical philosophical discourse, but rather to trace its genealogy by reconstructing the terrain on either side of it. This terrain is made of shifts in the very notion of explanation. Today, it is a terrain on which conflicting, seemingly incommensurable beliefs about the place and status of naturalistic scientific explanation20 coexist within a universe which it is acknowledged we still barely understand. My account is not guided by the attempt to find answers about the nature of consciousness or about the existence of souls in either man or animal. It focuses instead on showing the extent to which the construction of theories about cognition and the conscious mind is rooted in the historically shifting nature of the semantic ground on which we ask questions about ourselves - about our lives, our bodies and our world.21 It thus turns around the central matter of the status of the immaterial, rational soul at a point in history when the explanatory gap, this blind spot in our knowledge, was fully accepted, if not required within a theodicy. The ‘mind’ here, then, is not so much an object of scientific or philosophical enquiry as the very site of the blind spot, the blurred boundary between metaphysical and physical or biological enquiry, which sets the realm of modern philosophy, apart from the practice of experimental natural philosophy.22
4. Themes and outline
The study of this semantic ground on which we ask questions about ourselves - the very ground on which reason reveals itself to itself - constitutes the starting point of this dissertation and the subject of the first chapter. It presents the enquiries of Fellows of the Royal Society such as George Dalgarno, William Holder and John Wilkins into the role and status of language with regard to human knowledge, particularly through the case of the deaf persons’ ability to acquire it. Language was considered the most direct manifestation of higher cognitive faculties and was discussed as a manifestation of rationality within the dualist framework by the Cartesian lawyer Gérauld de Cordemoy, who presented language as proof of the dualist thesis. Fénelon discussed its acquisition in his treatise on the education of children. These enquiries touch on the question of whether or not language was a tool exceptional to humans. They are also related to worries about whether or not animals could be considered endowed with a mind comparable to that of humans. These worries - which correspond to our ‘other minds’ problem23 - and their historical background in the breakdown of the Aristotelian tripartite soul from Descartes onwards, are recounted in Chapter 2: it presents a study of the status of human reason within the new science and Cartesianism, via John Locke, Nicolas Malebranche and the Cartesian Louis De La Forge, and Pierre Bayle’s account of arguments put forth by Antoine Dilly and Ignace-Gaston Pardies about the border between animal and man. Malebranche and Locke reappear in Chapter 3, in discussions about the characteristics of animal minds following Descartes’s beast-machine thesis; Marin Cureau de la Chambre and Pierre Chanet follow, with earlier arguments about the distinction between, and respective definition of, reason and instinct.
The very definition of the human, as opposed to the animal, mind was thus presented in part as a linguistic issue. Moreover, the territory that language defined and described was the natural world. At stake in these enquiries, in the context of the practice of experimental, empirical, Baconian science, was the question of the knowability of this natural world and of our place in it, as well as the relationship between knowledge and human reason. The second part of the dissertation, in which the focus is mainly on natural philosophical works, takes off from here. The knowability of the world was debated within the framework of scepticism about the cognitive capacities of humans. This is the subject of the first Chapter in this section, with the study of works by the clergyman and Fellow of the Royal Society Joseph Glanvill, by Bernard le Bovier de Fontenelle (eventually Secretary of the Académie des Sciences in Paris) and by other notable natural philosophers including Robert Hooke. The role of teleology in shaping the functionalist assumptions underlying the investigation of the natural world (including the human body and brain) is analysed in Chapter 2, in relation to texts by the anatomists Nicolaus Steno and Thomas Willis and by the natural philosopher, natural historian and architect Claude Perrault (the brother of Charles, author of the famous Contes for children). This Chapter traces the shift in the use of teleological explanations of the relation between - visible or invisible - structure and - visible or invisible - function in the natural world, much studied by historians of science over the past decades. It prepares the ground for a look at the fate of debates about the rational soul - and thus, in modern terminology, of consciousness - in the context of the new mechanistic explanations of the motion of living and inert bodies. This is the subject-matter of Chapter 3, where the possibility of materialism is explored with the Parisian physician - and ‘libertin’ - Guillaume Lamy. All these issues, and in particular the recurrent problem of the status of animal minds, needed to be considered in an era that had not yet given birth to the ‘man-machine’, but which foresaw it with great anxiety. This essentially moral anxiety about the consequences of naturalism for the human soul was partly expressed in the difficulty of placing living, biological creatures somewhere on the long, complex continuum between the mechanical and the organic. This difficulty is still with us.
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