Journal of the History of Philosophy

BOOK REVIEWS 477 The Achilles of Rationalist Arguments. By Ben L. Mijuskovic. International Archives of the History of Ideas, no. 13. (The Hague: Martinus Nijhoff, 1974. Pp. 142) Much writing on the history of philosophy gets consigned rather contemptuously by many contemporary philosophers to what they think of as the history of ideas. For such philosophers , that phrase denotes a discipline that, while perhaps having some esoteric virtues of its own, is philosophically shallow and barren, lacking, as it often does, even an appreciation for, let alone a share in, the rigor and sophistication of contemporary philosophizing. Thus the phrase "the history of ideas" becomes a label used to mark what is thought of as second-rate, as "not quite philosophy." There is, however, a more literal, precise, and proper sense of that phrase that need carry no pejorative connotations of either philosophical naivet6 or mere antiquarianism. The aim of the enterprise, so understood, is to trace the life of philosophical ideas during some period whose intellectual climate they explicitly dominate or more subtly condition: sometimes to connect them to ideas standing in the same relation vis-a-vis earlier and later periods, discerning interesting continuities or discontinuities; and, in some cases at least, to explore what life remains in those ideas in our own time. There need be nothing second-rate about such an enterprise, one only those entirely insensitive historically could dismiss as of no interest to philosophy. All of these aims Professor Mijuskovic's book sets out to accomplish, focusing on an idea with a history stretching back to antiquity, but concentrating its attention on the seventeenth and eighteenth centuries, when, Mijuskovic claims, the idea became a pivotal one underlying much of the most interesting philosophical achievement of the period. The project is a laudable one in conception but regrettably much flawed in execution. An account of these flaws may have some bearing on the reasons for the dismissive view of the history of ideas I mentioned above, a point to which I shall return. The idea in question, regarded by Mijuskovic as a "unit idea" in Lovejoy's sense, is that of the essential simplicity of the soul (due to its immateriality as a thinking thing), together with the concomitant characteristics of indestructibility, unity, and identity. All of these taken together constitute what Mijuskovic calls "the simplicity argument"; and his project is to "'trace' the prevalence and influenceof this argument.., in the 17th and 18th centuries.., a time when it becomes crucial in questions concerning" (1) the immortality of the soul, (2) the unity of consciousness, (3) personal identity, and (4) the existence of an external world. After an introduction to the argument and its history prior to the period to be investigated, separate chapters are devoted to each of the four distinct uses Mijuskovic sees the argument as having in connection with these four distinct topics. Two complementary aims are pursued throughout the study: first, "to show that the simplicity argument was diffusely but pervasively present in the intellectual atmosphere of the 17th and 18th centuries and that it maintained in the age a status as impersonal as philosophic language itself," and second, that the four distinct uses mentioned can nevertheless be disentangled and their history and development followed separately. Mijuskovic's main conclusion concerning the early uses of the simplicity argument is that they were confined to arguments for the immortality of the soul and for the unity of consciousness . It is only in the seventeenth century that the argument begins to assume a central role in discussions of personal identity, and it is only then also that its idealistic implications begin to be recognized. Each of the four chapters devoted to the four modern uses of the argument contains material of interest, and most readers will find something instructive in one or another of them. They also display both the very real virtues and the unfortunate flaws in Mijuskovic's handling of his task. Limitations of space force one to be selective, so I shall single out the chapters on the unity of consciousness and on personal identity for a closer look, partly because these seem to be most central and distinctive to...