Note 23 — Chapter IV · AUTHORITIES FOR THE STOIC PHILOSOPHY: ITS PROBLEM AND DIVISIONS.

(b) Views of Zeno and Cleanthes. These views are mentioned as peculiar to Aristo, and as points in which he differed from the rest of his School; and, to judge from his controversial tone, the opposite views were those almost universally entertained by Stoics. That controversial tone, in fact, appears to have been directed not only against assailants from without—such as the Peripatetics and Platonists—but far more against those members of the Stoic School, who attached greater importance than he did to special ethical investigations, and to logical and physical enquiries. Among their number must have been Zeno and Cleanthes; for Zeno set the example to his School of dividing philosophy into logic, ethics, and natural science;23 witness the titles of his logical and physical treatises24 and also the statements in reference to theoretical knowledge and natural science which are expressly attributed to him. Moreover, Zeno himself recommended to others, and himself pursued, logical enquiries.25 Indeed, his whole mental habit,26 with its keen appreciation of even the subtleties of the Megarians, bears testimony to an intellectual type of thought which is far removed from that of Aristo.27 It was, moreover, Zeno who chose that curt and unadorned logical style, which is found in its greatest perfection in Chrysippus.28 Logical and scientific treatises are also known to have been written by Cleanthes,29 who, in his division of philosophy, allotted separate parts to logic, to rhetoric, and to natural science,30 and the name of Cleanthes is one of frequent occurrence, not only in the natural science, but more particularly in the theology of the Stoics. Still more exhaustive enquiries into logic and natural science appear to have been set on foot by Sphærus.31 These prove that the energies of the Stoic School must have been directed to these subjects before the time of Chrysippus, although these branches of science were no doubt subservient to ethics, whilst ethics held the most important and highest place in their philosophy. At a later time, when Chrysippus had expanded the system of the Stoics in every direction, and especial attention had been devoted to logic, the necessity for these sciences came to be generally recognised. More especially was this the case with regard to natural science, including ‘theology.’ All ethical enquiries must start, according to Chrysippus, with considering the universal order and arrangement of the world. Only by a study of nature, and a knowledge of what God is, can anything really satisfactory be stated touching good and evil, and all that is therewith connected.32