interval on estimation of its magnitude; the influence of nervous excitants, narcotics, and antipyretics on mental work; estimation of magnitude by the sense of touch; concomitant movements; a psychophysiological reflexion; pleasure and pain.
It will probably be long before another great and comprehensive work on Greek philosophy like that of Zeller will appear again. Ritter was supplanted by Brandis, and Brandis in turn has been supplanted by Zeller. But the comprehensiveness of the last named work, united with its unrivalled mastery of details, will for many years make a similar undertaking needless, and it seems probable that for generations the Berlin professor will hold the field against all comers. This, however, by no means precludes the usefulness of monographs on special subjects, and in this way much remains to be done. Several years ago Zeller expressed the wish that especially the post- Aristotelian philosophy might be subjected to a more searching investigation and criticism, and this book on the Middle Stoa comes to us in some measure fulfilling that wish. Schmekel has chosen an interesting subject, and has handled it in a masterful fashion. It is not a German monograph à la mode, filled with philological quibbles, learned lumber, and masses of undigested and ill-arranged facts mountain-high. The work is written with philosophical spirit and vigor; at the same time it exhibits a skilful employment of the right canons of historical criticism, and the hand of the precise philologist is not missed. Susemihl, in the preface to his History of Greek Literature in the Alexandrine period, mentions important help derived from Schmekel's volume, the MSS. of which he had used while preparing his history. (The Middle Stoa was published a year later than Susemihl's work.) The field covered by Schmekel is, to be sure, a small one, and at first sight one might be inclined to express both surprise and disapproval that a considerable octavo should be devoted to these later Stoics of whose writings very meagre fragments are extant. The book, however, is by no means a parallel to that monument of painstaking and misdirected genius, Lassalle's Herakleitos. In the first place, the fragments which we possess are considerably supplemented by explanations of later writers, and besides we have the fundamental doctrines of the Stoic
