Jamblique de Chalcis: Exétète et philosophe (review)

BOOK REVIEWS 101 could become a major criticism. Because this is simply a review, however, the caveats will remain small. First, it is by no means clear to me that Plato's astronomy, despite its "fantastic" features (ensouled universe, ensouled stars, etc.), did not provide a useful and (at least indirectly) testable model for understanding the motions of the heavenly bodies. Behind the talk about souls and their influence upon human souls, and so on, there are the testable (however difficult the testability may be to achieve) hypotheses that all the planets and the stars move with uniform and circular motion about a spherical earth. When these hypotheses were fully developed by Ptolemy, with the complete mathematical apparatus of deferents, eccentrics, epicycles, and even equant points, and also with the observations of Ptolemy and several of his predecessors, they proved incredibly fruitful. The "scientifically ascertained facts" of Euctemon and the others, without (at least) a mathematical model of stellar and planetary motion, while providing data to be explained, hardly provide one with anything appropriately called science. If we credit Euctemon and company with supplying more than observational data, since they did have means of discovering the differential periodicity of the times between solstices and equinoxes--whatever Plato's taste for the fastastic--we must recognize his acceptance of differential periodicity as acceptance of a great observational inconvenience to his general theory. Finally, I think it worth noting that, in the absence of any reason to develop a general theory of inertial motion, the idea of souls as movers animating bodies, including stars and planets, is not, as such, fantastic. Second, I am somewhat uncomfortable about what I think are two related matters, namely, Vlastos's acceptance of the notion that the Tirnaeus claim to be only a "likely story" constitutes Plato's denial of the possibility of serious physical science and the conception of science with which Vlastos approaches his subject. Concerning the first, it is by no means clear to me that the Timaeus, especially the section on the "compromise with necessity," is to be construed as a denial on Plato's part of the possibility of physical science. It is rather, I believe, to be construed as Plato's attempt to state the conditions under which physical science, as he understands it, can be possible. This attempt, with its invoking of the curious figure of the demiurgos, its mathematizing of the "unlimited" powers of the "receptacle," and so on stands in stark contrast to the relatively colorless accounts given in Philebus and elsewhere of what (the later) Plato claims to result in genuine knowledge or science, namely, collection and division. If Plato takes collection and division or the results of it to be or include science or knowledge of the physical world (and I think that he does), then most, if not all, of the Timaeus is not what Plato took to be science (physical or otherwise). As to what I take to be a "related matter," namely, Vlastos's conception of science, I think it is reasonably clear that he is working with a conception of science commonly associated with Hempel, Carnap, and others. I should take collection and division, with its associated apparatus of genera and species, real definitions, and so on, as an alternative conception of science. If I am right, though the present very brief comments by no means establish that, then the later Plato at least believes that there can be genuine physical science, and the Timaeus is not a disproof of that thesis. To raise these comments beyond the status of mere caveat would, however, require article-length argument and textual explication. ROBERT G. TURNBULL Ohio State University Jamblique de Chalcis: Exegete et Philosophe. By Bent Dalsgaard Larsen. (Aarhus, Denmark: Universitetsforlaget i Aarhus, 1972. Vol. 1, pp. 510. Vol. 2, pp. 137) This book, one of the many valuable contributions to the study of later Neoplatonism now appearing, comprises two volumes. The first, and by far the longer of these, surveys 102 HISTORY OF PHILOSOPHY Iamblichus's life and writings, both those preserved entire and those extant only in fragments, concluding with an account of his exegetic methods and their influence. The...