Introduction (1–24)

(1) The general character of the skeptical ability has been indicated with the appropriate treatment, sketched out in part directly and in part by means of a division of the philosophies close to it. What is left is to explain, next, how it is applied to the particulars, with a view to avoiding a reckless haste either when inquiring about things on our own or when rebutting the dogmatists. (2) But since philosophy is a many-faceted sort of thing, it will be necessary, for the sake of an orderly and systematic search, to draw a few distinctions concerning its parts.

The parts of philosophy (2–23)

For, to begin with, some people seem to have supposed that it has one part, some two parts, and some three parts; and of those who have posited one part some have posited the physical part, some the ethical part, and some the logical part, (3) and similarly of those who divide it into two some have divided it into the physical and the logical parts, some into the physical and the ethical, and some into the logical and the ethical; (4) whereas those who divide it into three have agreed in dividing it into the physical, the logical, and the ethical parts.

(5) The ones who maintained that it has just the physical part are Thales, Anaximenes and Anaximander, Empedocles, Parmenides, and Heraclitus – Thales, Anaximenes, and Anaximander according to everyone and without dispute, but Empedocles and Parmenides and also Heraclitus not according to everyone.