anuel Bekker, Berlin,
1842, has been used, with frequent consultation of the text of
J.A. Fabricius, 1718, which was taken directly from the existing
manuscripts of the works of Sextus. The divisions into chapters,
with the headings of the chapters in the translation, is the
same as Fabricius gives from the manuscripts, although not used
by Bekker, and the numbers of the paragraphs are the same as
those given by both Fabricius and Bekker. References to Diogenes
Laertius and other ancient works have been carefully verified.

The principal modern authors consulted are the following:

Ritter, _Geschichte der Philosophie_, II. Auf., Hamburg,
1836-38.

Zeller, _Philosophie der Griechen_, III. Auf., Leipzig,
1879-89.

Lewes, _History of Philosophy_, Vol. I., London, 1866.

Ueberweg, _History of Philosophy_, IV. ed., translated by
Morris, 1871.

Brochard, _Les Sceptiques Grecs_, Paris, 1877.

Brochard, _Pyrrhon et le Scepticism Primitive_, No. 5, Ribot's
_Revue Phil._, Paris, 1885.

Saisset, _Le Scepticism Aenesideme-Pascal-Kant_, Paris, 1867.

Chaignet, _Histoire de la Psychologie des Grecs_, Paris,
1887-90.

Haas, _Leben des Sextus Empiricus_, Burghausen, 1882.

Natorp, _Forschungen zur Geschichte des Erkenntnisproblems bei
den Alten_, Berlin, 1884.

Hirzel, _Untersuchungen zu Cicero's philosophischen Schriften_,
Leipzig, 1877-83.

Pappenheim, _Erlaeuterung zu des Sextus Empiricus Pyrrhoneischen
Grundzuegen_, Heidelberg, 1882.

Pappenheim, _Die Tropen der Greichischen Skeptiker_, Berlin,
1885.

Pappenheim, _Lebensverhaeltnisse des Sextus Empiricus_, Berlin,
1887.

Pappenheim, _Der angebliche Heraclitismus des Skeptikers
Ainesidemos_, Berlin, 1887.

Pappenheim, _Der Sitz der Schule der Griechischen Skeptiker,
Archiv fuer Geschichte der Philosophie_, I. 1, S. 47, 1887.

Maccoll, _The Greek Sceptics from Pyrrho to Sextus_, London,
1869.

My grateful acknowledgments are due to Dr. Ludwig Stein,
Professor of Philosophy in the University of Bern, for valuable
assistance in relation to the plan of the work and advice in
regard to the best authorities to be consulted. Thanks are also
due to Dr. Louisos Iliou, of Robert College, Constantinople, for
kind suggestions concerning the translation.

CONTENTS

CHAPTER I.

THE HISTORICAL RELATIONS OF SEXTUS EMPIRICUS ... 1

Introductory paragraph.--The name of Sextus Empiricus.
His profession.--The time when he lived.-