The Early Modern Subject: Self-Consciousness and Personal Identity from Descartes to Hume by Udo Thiel (review)

This monograph is an important book for anyone interested in the topic of consciousness and personal identity in early modern thought. It offers a rich overview of the vast array of writers reflecting on seventeenth- and eighteenth-century conceptions of persons, their responsibilities, the issue of immortality, and the development of an account of consciousness based on the way in which minds relate to their own thoughts and feelings. It traces the lines of influence from the scholastic background to Descartes and through French, Scottish, and German debates on consciousness and personhood. The book thus represents an impressive attempt at offering a complete account of the different ideas that were passed around and developed in Britain and on the Continent during the early modern period, and a sequel to this monograph focused on the second half of the eighteenth century is forthcoming. In its breadth and aspiration to include a great range of less commonly read figures, this book serves as an invaluable resource for specialized scholars as well as for those who want to attain an overview of the major fault lines along which the early modern debate developed. However, Thiel does not always spell out the implications of the accounts presented. He therefore often invites the reader to think of the relevant chapters as starting points for delving deeper into the intricacies of a specific theory and the way it did or did not engage with the thoughts of rival accounts at levels different from the ones discussed by Thiel.

Thiel’s method consists in putting into dialogue less known figures of early modern philosophy, such as Hermann Andreas Pistorious, Jean-Bernard Mérian, and Friedrich Carl Casimir von Creuz, with canonical writers like Locke, Leibniz, Hume, and Kant, thereby illustrating very comprehensively how certain core ideas associated with the great thinkers were born long before they appeared in their well-read works. By and large the book revolves around two thematic strands. The first strand investigates the different concepts of consciousness employed by early modern writers, focusing on the question of whether or not a given author endorsed a first- or second-order theory. The second strand looks at accounts of personal identity that either endorse or reject the view that identity is constituted by a substance.

The introduction covers the medieval scholastic debate, offering an interesting account of how questions about identity were originally tied to concerns about individuality but later, around the middle of the seventeenth century, were superseded by theories that discussed identity through time. Thiel links the nominalist tradition with the idea that only individuals exist. A new focus on the experience of individuals and the way this experience informs the formation of concepts is then seen as having shifted the debate away from “a primary ontological to a more subjective treatment of the topic” (25).

For Thiel, Locke’s account exemplifies this shift. It is, therefore, not surprising that his work constitutes the centerpiece of Thiel’s book, while accounts published before and after the Essay are analyzed in relation to Locke’s theory. By leading his readers through the many different responses to Locke, Thiel shows that the aspect of Locke’s theory that his contemporaries found hardest to digest was the claim that substances (either material, immaterial, or a combination of both) are irrelevant to the constitution of personal identity. Especially interesting in this context is the response of defenders of Locke. For example, Samuel Bold and Richard Burthogge sympathized with many aspects of Locke’s theory, yet both insisted that the continuity of the person requires the persistence of an ontological entity. A specifically Lockean account of personal identity here comes out as rejecting the substance view, while the claim that consciousness is constitutive of personal identity is taken to be the criterion that distinguishes Lockean from non-Lockean views.

At times the claim...