Excerpt from Transactions and Proceedings of the American Philological Association, 1909, Vol. 40 Heraclides of Heracleia in Pontus, a disciple of Plato, and Asclepiades of Prusa, a physician of the Ciceronian age, proposed a form of corpuscular theory of matter, which, after much discussion, is still a subject of many doubts. Some of these I hope to clear up in the course of this paper. The first question relates to our sources of information - the doxographic tradition. Beyond this, almost everything may be said to be doubtful, since conflicting testimony may be cited on almost every point. We cannot hope to make any progress, therefore, without first determining the relative value and credibility of our sources. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.