The Problem of Animal Generation in Early Modern Philosophy (review)

This rich volume aims at helping historians "to gain a fresh perspective on some of the basic problems of early modern philosophy," by studying how these problems manifest themselves in discussions of animal generation. The seventeen contributions are assigned to seven chapters, each consisting of two to four essays. Although the general introduction adequately introduces the types of problems that animal generation gave rise to, it unfortunately fails to explain the underlying reason(s) for this division. The basic structure, however, is chronological, and contributions range over William Harvey to Immanuel Kant. The editor clearly made an effort to turn the volume into a coherent whole, and overall he has done an admirable job. To illustrate this, I will briefly discuss a thematically organized selection of the contributions.

Annie Bitbol-Hespériès' contribution to the opening chapter introduces the problem of monsters, and aims to show—curiously without using a single footnote—that in the seventeenth century, natural philosophy begins completely to replace theology when it comes to explaining the existence of monsters. Her conclusion is confirmed by Justin Smith's own contribution to the second chapter ("The Cartesian program"), in which the problem of monsters is indeed taken up in the general context of a discussion of heredity. Smith convincingly shows that in the mechanistic embryology of Descartes and his followers, the role of Aristotle's vis formativa in explaining why like begets like is partly taken over by the imagination. Thus, the mother's imagination transmits ideas to the fetus during pregnancy, which explains both the normal inheritance of features and the formation of monsters (which result from the transmission of disturbing images). Importantly, imagination was not considered to be an occult force, but a bodily phenomenon. Saul Fisher's contribution to the next chapter ("The Gassendian Alternative") completes the picture of inheritance by focusing on Gassendi's miniature material souls (animulae), which transmit ontogenetic information from each parent to their offspring. Although Gassendi also leaves room for a divinely-created immaterial soul, Fisher argues that Gassendi's central commitment is to "a broadly materialist story" of the origins of individuals and inheritance (123).

The difficulty in accounting for animal generation in purely mechanical terms is illustrated by Vincent Aucante, who describes Descartes' experiments on eggs in his effort to do just that. Aucante interprets Descartes' failure to achieve any definitive results as, above all, a sign of his "realistic caution" (79). In an impressive contribution, Andrew Pyle continues Aucante's narrative by discussing Descartes' posthumously published De la formation de l'animal, in which he developed an ambitious epigenetic account, which failed, however, to convince his contemporaries. Pyle then continues to show how partly as a result of this failure, and partly as a result of microscopic discoveries, the theory of the preexistence of animals became more popular and was defended, for instance, by Régis and Malebranche. The microscopic discoveries were not, however, used by Malebranche as direct evidence for his preexistence theory, but rather as a means to show that such a theory is a plausible option.

The theme of epigenesis versus preexistence is touched upon in many of the contributions. The famous Haller-Wolff debate on the topic, for example, is discussed by Karen Detlefsen, who rightly takes a nuanced view on the distinction between epigenesis and preexistence. There is, she states, a "strong strand of preexistence theory in Wolff's mature view" and a "tremendous development of the fetus on Haller's view" (261). Francesco Paolo de Ceglia, by contrast, shows in his contribution on Georg Ernst Stahl that not everyone was equally interested in the correct account of the origin of animals. Stahl, like many physicians of his time, claims that physicians need not know about the precise origins of life, since such knowledge does not aid therapeutic practice.

The final two chapters are devoted entirely to Kant and include...