Ann Thomson's Bodies of Thought is simultaneously an outgrowth of her prior work and a new direction in her scholarship. She has done rigorous and original study of the mid-eighteenth-century French materialist Julien Offray de La Mettrie, offering important critical editions and major articles. She also has done fruitful studies of broader issues of eighteenth-century medicine, vitalism, Epicureanism, and clandestine literature. These endeavors immersed her in precisely the consequences—both intended and unintended, in France, above all—of the sorts of debates that she examines here. She knows well the early modern issues and implications of debates about mind and body, and she can explain them with precision and fluency.

Instead of assuming, as many have done, that the main sources of the French authors who have captured so much attention led self-evidently to prior Continental sources, she unravels here the complexities of sources, and she locates seminal influences upon French formulations in seventeenth-century English debates about the nature of the soul. She makes the case—empirically, analytically, and compellingly—that it is neither in a Spinozist “Radical Enlightenment” nor in a French libertine tradition that we shall find the origins of those materialist models of thought that arose with such drama in the course of the French eighteenth century. The evidence leads her back to British theology, medicine, politics, and complex polemics, and she follows that evidence to bring us a new and convincing account of filiations, affinities, and consequences.

Thomson's thick empirical, comparative, and analytic study is quite distinct from recent works that touch on the history of thinking about mind. It does not address the issues of understanding identity and consciousness that concern Raymond Martin and John Barresi in their striking The Rise and Fall of Soul and Self: An Intellectual History of Personal Identity (New York: Columbia University Press, 2006), which takes us from Athens through the Patristics, to the Renaissance and the early modern age. The focus for Martin and Barresi is on tidal changes in theories of personal identity. Thomson does not address the genealogy of modern (indeed, postmodern) theories of the self, as done in Jerrold Siegel's magisterial The Idea of the Self: Thought and Experience in Western Europe since the Seventeenth Century (Cambridge: Cambridge University Press, 2005). Siegel presents early modern debates with historical rigor, but he is interested in the “major” thinkers whose influence is acknowledged into the current age itself, and he wishes to understand, above all, how we got to present dilemmas and conceptions. Thomson keeps an eye on the future, aware of the longer-term influence of her subjects, but her goal is to explore a very particular moment of the history of European thought. Further, her focus is not on “self,” or identity, but on the specific debates that pertained to issues of the substance and relationship of body and mind, as conceived in philosophy, theology, and medicine, as argued in those and in political contexts, and as transmitted and appropriated in and by the early modern learned world.

Bodies of Thought is a singular and compelling study of early Enlightenment debates about the nature of soul and mind, about the relationship of thought to body, and about the shape and status of human knowledge of such entities and phenomena. It grounds these issues, contextually, in contemporaneous debates in politics, science, and religion (the word “politics” rightly should be in its subtitle), and in contemporary polemic, apprehensions, and anxieties concerning the implications of these debates for society, for the advancement of knowledge, and for religion. It follows these debates from England, where they agitated so many seventeenth- and early eighteenth-century minds, to France, where they assumed particular urgency in the early eighteenth century and crucially shaped later Enlightenment formulations and contentions. Thomson focuses primarily on the profound roles of English and French thinkers and polemicists, concerned also with the means of communication and appropriation between England and France. She also keeps an eye on the larger European Republic of Letters when Dutch or German influences, for example, affected English and French readers.

Enlightenment studies in general, and, more recently, “early Enlightenment” studies in particular, are, to say the very least, what are termed today “contested” fields. The divisions, uncorrelated generally, are roughly between contextual or teleological history (in the latter case, anticipations of something the author deems awesome); between monographic and synthetic studies (the latter alone earn one an adjective or one's name before the word “thesis” these days); and between works that seek a climate or variety of climates of perspective, on the one hand, and, on the other, works that filter a variety of early modern authors through the purported direct influence of some great mind (Locke, Hobbes, Newton, Spinoza, or Bayle, for example). In that scholarly context, Thomson achieves a wonderfully nuanced place. She is a contextualist, but she never loses sight of how her contemporaneous debates, understood in their own time and appropriations, shaped what would come after. She is the author of a monograph, but she has cast her net so widely—she knows from arduous research who is reading and responding to whom—that her work becomes a picture window onto one of the defining issues of the age. She never assumes direct influence, but she understands just how diversely the same work, to different minds and in different configurations, contributed in various ways to particular and general considerations. That accomplishment is a rare tour de force.

In some ways, Thomson is unduly modest about her achievement. She wishes to avoid the meta-claims and premature syntheses of early modern intellectual history as frequently (and currently) practiced. Nonetheless, she is focused on a question that seventeenth- and eighteenth-century thinkers addressed both with urgency and with a sense of the deepest conceptual stakes and their significant implications. They were asking nothing less than how far could one go in understanding mental phenomena in terms of behaviors of the natural body? Thomson does not want to wander too far from the topic of soul to the topic of God (beyond her rightly explaining in great detail how charges and countercharges of “atheism” arose from diverse discussions of soul). Nonetheless, what authors diversely thought about what either must or need not be attributed to immaterial substance, the soul, parallels the early modern obsession with what must or need not be attributed to the agency of God. Early modern European educated culture was acutely aware of the promise and dangers of increasingly naturalistic explanation of the world, and, in particular, of increasingly materialistic explanation. Questions of soul and body evoked the same immeasurably fearsome concern that issues of physical phenomena and divine activity raised: the problem of naturalism. A sense of that larger context adds yet more importance to Thomson's work as a study of both early modern polemic and early modern philosophical and theological unease.

The specter, if I might offer that context, always had been absolute naturalism, the elimination of God and the supranatural from an understanding of the reality in which humanity found itself. This was, for most believers of the early modern world, the worst error that a mind could make. The culture had quite diverse understandings of what views achieved that awful state, but it generally agreed on its ultimate philosophical form. For the atheist, the world existed, persisted, and proceeded by its own forces of matter-in-motion, without creation, design, dependence, or governance by any being that transcended the natural order; that is, without relationship of any kind to an independent God.

The term “naturalism” is problematic and equivocal in the history of thought, and the seventeenth century rendered it yet more ambiguous, but to so many early modern minds it simply was folly, blindness, and wickedness to explain the world solely in terms of purely natural agencies. In the Summae Theologiae, St Thomas Aquinas had formulated only two essential and general objections to proof that God existed: the presence of evil, and the sufficiency of natural explanation. In terms of the second objection, Thomas argued that if the “effects of nature” could be explained solely in terms of “natural causes,” then there would be no need to infer the existence of God.

Although the context had altered radically from Aquinas's theoretical atheist to the English context of the seventeenth century, the Cambridge Platonists, nonetheless, famously argued (with Hobbes in mind) that sorcery and enchantments served the glorious purpose of establishing an evidence of supranaturalism sufficient to defeat atheism. Henry More identified the problem of naturalism as the belief that nothing transcended or existed independently of nature, and that “matter in motion,” existing independently, could account both for the formation of plants and animals and for the intellectual phenomena of mind, memory, and imagination.

For the early modern learned world, however, there was, to say the least, no crime in explaining phenomena by examination of natural forces believed to bear witness to the infinite power and wisdom of God, and there was nothing to be gained by having recourse to direct divine agency when the laws of nature sufficed to explain a phenomenon. Indeed, such unnecessary recourse frequently was accounted “superstition.” However, it was essential to see those laws of nature as inexplicable without God as original cause. The debate over the extent to which body could explain mental life in many ways mirrored and touched upon this same set of concerns and pursuits of natural knowledge. In short, Thomson's issue of body and mind—and I wish that she had made this claim— was part of the most essential debate of which an early modern thinker could conceive.

In seventeenth-century France, for example, there was a continual mutual reductio ad naturalismum among competing schools of philosophy. It was the most direct route to discrediting one's rivals. Whatever the argument for or against the latent naturalism of various philosophies, it was historically the case that the widely read Aristotelian, Cartesian, and Malebranchist French philosophers and polemicists of the late seventeenth century virtually all saw themselves as wholly orthodox. It was not the Aristotelians who insisted upon naturalist conclusions from Aristotelian thought. Quite to the contrary, they insisted on the virtual indispensability of Aristotelian philosophy to Christian theism. It certainly was not the Cartesians who drew naturalist conclusions from Descartes, nor the Malebranchists who drew naturalist conclusions from Malebranche. Again, each camp saw itself as a pillar of theistic orthodoxy. Rather, the proponents of each system, proclaiming their school alone to be the appropriate voice for Christian culture and education, also claimed to see a logical naturalist conclusion to the thinking of each rival philosophy. It was in the actual, historical context of early modern debates, passions, and polemics that the culture generated the model of an atheism triumphing over (the other's) Aristotelianism, (the other's) Cartesianism, and (the other's) Malebranchism. The dialecticians of early modern learned France could teach each other with relentlessness and skill to find the atheistic naturalism of each other's doctrines. Then, with no one intending it, those lessons were part of the culture, there for the taking. There was no small degree of a similar phenomenon in the seventeenth-century British polemics over soul and body (could one account for human mental phenomena without reference to immaterial soul?) that Thomson analyzes so skillfully, even if certainty about there being no intentionality is not so similarly apparent.

For Thomson, however, it is crucial not to overreach: she is writing a history not of materialism, but of debates about the extent to which human phenomena could be explained in terms of body alone. Further, she wishes to understand those debates not as they appear in the light of contemporary (as opposed to contemporaneous) concerns, but as they were understood by the actors in those debates themselves, exploring early modern contexts and early modern meanings. If that sheds light on future developments (which it does), so much the better, in her view, but this is early modern history. Such a focus rightly leads her away from the themes of the nineteenth to twenty-first centuries. Rather, it brings her to seventeenth-century considerations: to the “mortalist” heresy, revived, in the minds of many, by Milton in Paradise Lost (that the soul and body die simultaneously and are later resurrected simultaneously); to work in physiology and anatomy (with close attention to questions of reproduction and to the study of the brain) and to intense disputes about the relationship of such work to issues of theology and philosophy; to metaphysical speculations and arguments on active matter and on what was and was not congruent with a dualism of mind and body; and to increasingly forceful and explicit discussions of the actual nature of “the soul.”

In tracing the polemics incited by these phenomena, Thomson's criterion of selection is rightly not to analyze those polemicists whose reputations necessarily still endure, but those who can be identified as central to the actual debates of the early eighteenth century. Thus, in addition to analyses of John Toland and Samuel Clarke, we find close readings (and explanations of the centrality) of figures such as Henry Layton and William Coward. All of these debates, Thomson shows, intersected, in diverse and influential ways, passionate religious and ecclesiastical controversies, in which accusations of freethinking were of great use to participants. These English phenomena, she demonstrates convincingly, were transmitted to France via the complex networks of the Republic of Letters, in which Holland played a major role, where, in a very different context, they were diversely appropriated and helped to shape the varieties of later French materialism. For Thomson, the question at hand is rightly of singular importance—what secular views of being a thinking human had emerged by the later Enlightenment?—and she explains, with great success, both the nature of those views and how they came to be formulated specifically as they were.

There are an increasing number of scholars in French intellectual, literary, and philosophical history who focus on the clandestine manuscripts that circulated in France in the early to mid-eighteenth century. There is, alas, a tendency to fetishize these manuscripts, as if the reason for their clandestinity could only be some elevated importance, heterodoxy, or uniqueness. In fact, in France as in England, the flow of heterodoxy was usually from published works to clandestine manuscripts, not the reverse.

Thomson, who herself has contributed to the literature on clandestine manuscripts, understands full well both the problematic nature of classifying and categorizing these texts and the unanswered questions about why certain texts appear in published or in unpublished form (or, indeed, in both). Just as she resists the impulse to place a great figure at the center of her account, so, when she turns to France, does she resist—indeed, knowingly reject—the temptation to place the clandestine manuscripts on the nature of the soul at the center of the flow of ideas in France. She explains, instead, how currently notorious manuscripts such as L'Ame materielle were themselves eclectic and were themselves indebted to works that circulated openly.

This is a work of great erudition and deft scholarship, but it is an interesting work with which to debate, and it is a work with several substantive and structural problems. To begin with the latter, there are too many roadmaps for the reader, and there are too many side debates with the prevailing historiography and with individual monographs (though many readers will find all that to their liking).

Substantively, and of greatest importance analytically, Bodies of Thought does not always distinguish epistemological from ontological claims. That is to say, it is not a difference in name only to claim, on the one hand, that one may not make a certain assertion about the structure of the world because we cannot know such things, or to claim, on the other, that one may not make a certain assertion about the world because we know, from the real nature of things, that such an assertion would be false. When Locke wrote that we could not know the real essence of mind, he was making a claim about the limits of human knowledge. When he wrote about human phenomena, however, he clearly leaned toward a dualism without which those phenomena seemed inexplicable to him. Indeed, Locke seemed wholly inclined toward such a dualism in terms of the kinds of beings (material and immaterial) that existed in the world. His theory of knowledge, however, insisting that we could not know, from our sense-experience, the real nature of those seeming substances (matter and spirit) that lay beneath appearances, prevented him from extending philosophy's claims to ontological knowledge. In Locke's case, thus, epistemological modesty prevented ontological assertions. In Hobbes's case, to the contrary, a very strong argument can be made that his claim, on nominally epistemological grounds, that all talk of “soul” or “immaterial substance” was “non-sense” and “mere sounds,” masked a deeper ontological (in his case, materialist) agenda. In Thomson's work, however, it is not always clear when authors are talking about what they believe to be the limits of certainty and when they are stating what they believe to be the actual nature of the substantial world. One needs to analyze such things, however, truly to understand a philosophical position.

The work also fails to address clearly the dramatically different circumstances faced by Catholic and Protestant thinkers on the subject of the immortality (and, hence, most believed, immateriality) of the soul. For Catholics, the Eighth Session of the Lateran Council of 1512 had proclaimed the demonstrability of the immortality of the soul by natural reason. It became, somewhat paradoxically, an article of faith for orthodox Catholic thinkers to believe that the immortality of the soul was knowable by natural reason. For Protestant thinkers, there was always a fideistic option, believing by faith alone in an immortality of soul that one did not believe naturally demonstrable. Thomson writes (49 and 58) as if the Lateran Council were somehow binding upon Protestants (she knows it was not), where, in fact, the option of a pious philosophical skepticism made the stakes of philosophical demonstration of the immateriality of the soul far less high in England than in France. She needed to sort out what could be praeambulae fide and what were articles of faith in the Protestant and Catholic worlds she explores.

Her use of the critically important term “Socinian” (critical both for the evolution of English religious thought and for an understanding of English polemics) is equivocal, sometimes appearing to stand for followers of Socinus's “Racovian Catechism,” sometimes for any variant of Protestant Arianism, sometimes for any and all anti-Trinitarian thought, from self-proclaimed Christians who accepted Christ as the messiah to speculative freethinkers who went beyond all Christian boundaries.

In terms of the arguments worth having with Thomson, the most significant is over her discussion of Hobbes. In her desire to escape the overestimation of the role of single authors, she seriously underestimates, I believe, the direct and indirect influence of Thomas Hobbes in shaping both English and French discussions of the soul and the problem of materialism. Hobbes was probably the single most important catalyst in producing the recoil of the Cambridge Platonists—More, Glanvill, and Cudworth, in particular—away from their initial attraction to Descartes and his mechanistic physics and physiology. The shadow of Hobbes colored all of their considerations of these issues. In the case of France, the influence was direct and acknowledged. Holbach read and purchased Hobbes's De Homine while in England; he translated it into French in 1772. When he introduced Diderot to Hobbes via that Traité de la nature humaine, Diderot wrote to Naigeon that Locke “seems to me diffuse and cowardly in comparison with this Thomas Hobbes . . . It is a book to read and to comment upon all of one's life.” For Naigeon, writing in his Mémoires sur Diderot and in his Philosophie ancienne et moderne, after reading Hobbes's De Homine, Condillac now appeared to be a pure idealist in his analysis of mind, and Hobbes simply brought Lockean philosophy to ineluctable materialistic conclusions. Naigeon informed readers that Diderot had written the article “Hobbes” in the Encyclopédie before he had read De Homine, “one of the most beautiful works ever issued from the human mind.”Footnote ¹

Thomson also undervalues, I fear, the role of published ancient texts and fragments, and of seventeenth-century histories of philosophy themselves, in these debates. Ancient and Patristic figures—and the opponents whose views they described or cited—were often contemporaneous voices in the early modern learned world. She pays inadequate attention to the curricula of universities and seminaries, although these may well have demonstrated the continuities or discontinuities of certain debates and formulations. It is difficult to know where thinkers become innovative if one does not examine what they were previously taught.

These are perhaps merely pedantic quibbles, however, given the sweep and strength of Thomson's study and the sequence of textually and contextually informed and compelling discussions and analyses from beginning to end. Her discussions of borrowings, appropriations in differing contexts, and influence are both erudite and cautiously aware of the problematic nature of such claims. She subjects historical theses about politics and thought to rigorous scrutiny, pointedly showing the philosophical, religious, and political affinities that should not exist (but do) if the synthetic historiography were true. For those in the field, there are treasures in every chapter and section.

For all readers, the work opens important windows upon the emergence of early modern and hence modern views of human mind, body, and being. The whole discussion of La Mettrie alone, in terms of his formation, his thought, and his influence, is worth the price of admission. Her discussions of Jonathan Israel's thesis of a “Radical Enlightenment” that was Spinozist at its core are judicious and persuasive, and always argued in the context of actual debates, contexts, and texts. Her analyses of seventeenth-century study of and thinking about the physical brain are enlightening and convincing, and she offers subtle, original, and strikingly documented views about the relationship of such medical and anatomical concerns to religious and theological debate. When, in an “Epilogue,” she speculates on the “consequences” of early modern materialist views of man, she identifies and locates the deep moral concerns of thinkers such as Diderot and Naigeon, showing how the efforts of late Enlightenment materialists to solve their moral dilemmas anticipated and perhaps made possible the naturalistic humanism that was to come. Breaking with a whole tradition of French historiography that assumed the affinity of materialism and incipient egalitarianism, she reveals how, for influential late Enlightenment materialists, a focus on physical and physiological causation of differences could explicitly support notions of natural inequality.

We live in a moment of scholarly fashion that wrongly values hasty synthesis over the kinds of analytic works and monographs that alone could make such syntheses both informed and, thus, of legitimate interest. Thomson's Bodies of Thought demonstrates with full force the essential value of patient, careful, rigorous, analytic, and clearly focused scholarship. In normal times, it would be perhaps absurd to think of this work as a “monograph.” It examines generations of thought—in England and in France—about a central concern of human identity and knowledge, the relationship of body and mind. It pursues this concern into the domains of theology, medicine, anatomy, religion, philosophy, ethics, and politics, dealing explicitly with the thorny issues of transmission of ideas, influence, shifting climates of opinion, authorial intent, and unintended consequences. It is informed by the reading of hundreds of texts essential to the formulation of these ideas and by the rich scholarly literature around these themes. What makes it monographic, in the best sense of that term, is that it knows the limits of its subject and of its own knowledge, it gives the readers the evidence required to agree or disagree, and it places human thought in the specific contexts from whose problems and choices that thought emerged. These days, that is a stunning achievement in itself.

Much scholarship today obsesses on the development of notions of human nature. It appears to be a great temptation, however, for historians and critics to become anachronistic to the point of being ahistorical, imposing present-day debates and concerns on a past that would not have conceived of even the categories of such imposed characterizations. It also appears to be a great temptation to seek in the past the building blocks of one's favored modern theories in a distorted and tendentious selective borrowing from the works of authors who exhilarated or shocked their own contemporaries for reasons having nothing or little to do with modern ways of organizing knowledge.

What makes history so significant, however, is that it is our meeting of our human brethren in their own other times, other places, and other contexts, permitting us to encounter human life in its genuine variety. Nowhere is that meeting more dramatic than in the domain of human thought—our means of mediation between self and nature, and, along with humor, its cousin, that which most separates us from the other primates. That mediation gives us not merely an evolutionary or geological history, but, from those perspectives, those short-term changes that, in fact, we term “history.”

If we could transport ourselves back to the past, we would figure out sex and sexuality (or at least as well we figure it out today), we would learn how to earn a living, we would understand to whom we owed deference and whom we'd best obey. That's not the truly mysterious stuff. It would be how people thought about, understood, and explained the world that would be the most elusive aspect of another time and culture.

Indeed, for all of the current fixation on “the other,” modern scholars too often miss the most “other” of all, the historical other—human beings in their own lives, to be discovered—our forebears in their own worlds and mental climes. It is Thomson's great achievement that she allows such an encounter to occur. One understands the impulse to demonstrate how we got from there to here. If someone is to do that, however, he or she will have to know the “there.” Perhaps drawing the lines is possible; perhaps not. The excitement, for historians, and the sine qua non of possible broader answers, is to understand the human mind as it behaved before our arrival on the current scene. Bodies of Thought detaches itself from the teleological and ideological imperatives of the present, and it seeks, successfully, to introduce us to that actual behavior.