Galileo and His Sources: The Heritage of the Collegio Romano in Galileo’s Science by William A. Wallace (review)

BOOK REVIEWS Galileo and His Sources: The Heritage of the Collegio Romano in Galileo's Science. By WILLIAM A. W.ALLACE. Princeton: Princeton University Press, 1984. Pp. xii + 371. $42.50. In the past two decades we have seen a proliferation of studies on Galileo and his influence in philosophy and modern science. Wallace's latest work, Galileo and His Sources, is actually the third book he has devoted to this subject, the two previous being Galileo's Early Notebooks (Notre Dame: 1977) and Prelude to Galileo (Reidel: 1981). It represents the summit of his achievement, and indeed makes an invaluable contribution toward understanding all of Galileo's writings and the sources from which they ultimately derived. This is especially true with respect to the early Latin notebooks of the famous physicist, usually ignored by scholars on the basis that they are irrelevant to an understanding of his major later writings and the " new science " of motion. Wallace's assessment is quite different. The first part of his volume is devoted to studying these Latin notebooks and exploring the tradition within which they originated. For Wallace, such research is indispensable for understanding and evaluating Galileo's later work. After years of investigation he has discovered that the early notebooks, containing questions on logic and methodology as well as questions on the universe and the elements, show remarkable parallels with manuscript notes of lectures given by Jesuit professors at the Collegio Romano in the last decades of the sixteenth century. Galileo was undoubtedly influenced by the teaching of these men, most of them in their mid-twenties, whose philosophical position he characterizes as that of "progressive Aristotelianism." Wallace documents their influence in an original and remarkable analysis of their surviving lecture notes, showing how they were appropriated by the young Galileo when writing his logical and physical quesions. Perhaps the most significant of Wallace's discoveries is that Galileo composed these notes in the period between 1588 and 1591, while he was already teaching mathematics and astronomy at the University of Pisa or actively preparing for that post-and not while he was a student either at the Monastery of Vallombrosa or at the University of Pisa, as previously had been thought. This makes the logical and physical questions practically contemporaneous with Galileo's writing of his early treatises on motion, preserved in another Latin manuscript usually dated ca. 1590, which has long been seen as preparatory to the analysis of local motion given in his Two New Sciences of 1638. ~89 290 BOOK REVIEWS Such painstaking textual research occupies the first two parts of the volume, in our opinion its most valuable contribution. Here the scholarship involved in Wallace's scrutiny of these sources is simply extraordinary, involving as it does knowledge of paleography as well as the intricacies of scholastic logic and natural philosophy. Every possible extant source, most of them in manuscript, is analyzed, explained, and compared in detail with Galileo's own notes-all in his own hand and thus of undoubted authenticity. The first chapter of the first part deals with Galileo's logical questions, actually 27 queries arising from Aristotle's treatment of demonstration and its prerequisites in his Posterior Analytics; the second, with 25 additional questions relating to matters treated in Aristotle's De caelo et mundo and his De generatione et corruptione. The amount of data uncovered, its organization and careful evaluation, would alone suffice to make this volume a signal contribution to Galileo studies. Subsequent researchers in this field simply cannot afford to ignore it. And not only is it important for understanding Galileo's contribution to early modern science; it is also of value for intellectual history generally, for, Galileo studies aside, ·Wallace's examination of the writing of these Jesuits at Rome is itself a positive (and quite unexpected) contribution to the histories of natural science and natural philosophy. The second part of the volume expands the textual analyses of the first part to explore in fuller detail the logic and natural philosophy being taught at the Collegio Romano and how these impacted on the methodological problems raised by the prospect of a " new science " of local motion. In other...