 A word, first, about the provenance and evidential value of the Aristocles passage. Several chapters from book 8 of Aristocles’ Peri philosophias (On Philosophy) appear in quotation in the Praeparatio evangelica of Eusebius, the fourth-century bishop of Caesarea. These chapters expound, and then attack from an Aristotelian perspective, a number of philosophies that impugn the reliability of one or other of our cognitive faculties. Among these Aristocles counts Pyrrhonism, as represented by Pyrrho himself and by the initiator of the later Pyrrhonist tradition, Aenesidemus; Aristocles speaks of Aenesidemus (first century BCE, q.v.), as recent, and is apparently not aware of any subsequent members of the Pyrrhonist tradition. The chapter on Pyrrhonism opens with a brief summary of the early Pyrrhonist outlook, as reported by Timon, who refers to Pyrrho (14.18.1–5).