[1] Pappenheim Leb.  Ver.  Sex.  Em. 6.

In regard to the exact time when Sextus Empiricus lived, we gain very little knowledge from internal evidence, and outside sources of information are equally uncertain.  Diogenes Laertius must have been a generation younger than Sextus, as he mentions the disciple of Sextus, Saturninus, as an Empirical physician.[1] The time of Diogenes is usually estimated as the first half of the third century A.D.,[2] therefore Sextus cannot be brought forward later than the beginning of the century.  Sextus, however, directs his writings entirely against the Dogmatics, by whom he distinctly states that he means the Stoics,[3] and the influence of the Stoics began to decline in the beginning of the third century A.D.  A fact often used as a help in fixing the date of Sextus is his mention of Basilides the Stoic,[4] [Greek:  alla kai oi stoikoi, os oi peri ton Basileiden].  This Basilides was supposed to be identical with one of the teachers of Marcus Aurelius.[5] This is accepted by Zeller in the second edition of his History of Philosophy, but not in the third for the reason that Sextus, in all the work from which this reference is taken, i.e.  Math.  VII.-XI., mentions no one besides Aenesidemus, who lived later than the middle of the last century B.C.[6] The Basilides referred to by Sextus may be one mentioned in a list of twenty Stoics, in a fragment of Diogenes Laertius, recently published in Berlin by Val Rose.[7] Too much importance has, however, been given to the relation of the mention of Basilides the Stoic to the question of the date of Sextus.  Even if the Basilides referred to by Sextus is granted to have been the teacher of Marcus Aurelius, it only serves to show that Sextus lived either at the same time with Marcus Aurelius or after him, which is a conclusion that we must in any case reach for other reasons.

    [1] Diog.  IX. 12, 116.

    [2] Ueberweg Hist. of Phil. p. 21.

    [3] Hyp.  I. 65.

    [4] Adv.  Math.  VII. 258.

    [5] Fabricius Vita Sexti.

    [6] Zeller Op. cit.  III. 8.

    [7] Brochard Op. cit.  IV. 315.

The fact that has caused the greatest uncertainty in regard to the date of Sextus is that Claudius Galen in his works mentions several Sceptics who were also physicians of the Empirical School,[1] and often speaks of Herodotus, supposed to be identical with the teacher of Sextus given by Diogenes Laertius,[2] but makes no reference whatever to Sextus.  As Galen’s time passes the limit of the second century A.D., we must either infer that Sextus was not the well-known physician that he was stated to be by Pseudo-Galen, and consequently not known to Galen, or that Galen wrote before Sextus became prominent as a Sceptic.  This silence on the part of Galen in regard to Sextus increases the doubt, caused by Sextus’ own criticism