This is not the only place in the writings of Sextus which states that Aenesidemus at some time of his life was an advocate of the doctrines of Heraclitus. In no instance, however, where Sextus refers to this remarkable fact, does he offer any explanation of it, or express any bitterness against Aenesidemus, whom he always speaks of with respect as a leader of the Sceptical School. We are thus furnished with one of the most difficult problems of ancient Scepticism, the problem of reconciling the apparent advocacy of Aenesidemus of the teachings of Heraclitus with his position in the Sceptical School.
A comparison with each other of the references made by Sextus and other writers to the teachings of Aenesidemus, and a consideration of the result, gives us two pictures of Aenesidemus which conflict most decidedly with each other. We have on the one hand, the man who was the first to give Pyrrhonism a position as an influential school, and the first to collect and present to the world the results of preceding Sceptical thought. He was the compiler of the ten Tropes of ἐποχή, and perhaps in part their author, and the author of the eight Tropes against aetiology.[1] He develops his Scepticism from the standpoint that neither the senses nor the intellect can give us any certain knowledge of reality.[2] He denied the possibility of studying phenomena as signs of the unknown.[3] He denied all possibility of truth, and the reality of motion, origin and decay. There was according to his teaching no pleasure or happiness, and no wisdom or supreme good. He denied the possibility of finding out the nature of things, or of proving the existence of the gods, and finally he declared that no ethical aim is possible.
[1] Hyp. I. 180.
[2] Photius 170, B. 12.
[3] Adv. Math. VIII. 40.
The picture on the other hand, presented to us by Sextus and Tertullian, is that of a man with a system of beliefs and dogmas, which lead, he says, to the philosophy of Heraclitus. In strange contradiction to his assertion of the impossibility of all knowledge, he advocates a theory that the original substance is air,[1] which is most certainly a dogma, although indeed a deviation from the teachings of Heraclitus, of which Sextus seemed unconscious, as he says, τὸ τε ὄν κατὰ τὸν Ἡράκλειτον ἀήρ ἐστιν, ὡς φησὶν ὁ Αἰνησίδημος. Aenesidemus dogmatised also regarding number and time and unity of the original world-stuff.[2] He seems to have dogmatised further about motion,[3] and about the soul.[4]
If Sextus' language is taken according to its apparent meaning, we find ourselves here in the presence of a system of beliefs which would be naturally held by a follower of the Stoic-Heraclitan physics,[5] and absolutely inexplicable from the standpoint of a man who advocated so radical a Scepticism as Aenesidemus. Sextus in the passage that we first quoted,[6] expresses great indignation against the idea that Scepticism could form the path to the philosophy of Heraclitus, but he does not express surprise or indignation against Aenesidemus personally, or offer any explanation of the apparent contradiction; and while his writings abound in references to him as a respected leader of the Sceptical School, he sometimes seems to include him with the Dogmatics, mentioning him with the δογματικῶν φιλοσόφων. [7] In fact, the task of presenting any consistent history of the development of thought through which Aenesidemus passed is such a puzzling one, that Brochard brilliantly remarks that possibly the best attitude to take towards it would be to follow the advice of Aenesidemus himself, and suspend one's judgment altogether regarding it. Is it possible to suppose that so sharp and subtle a thinker as Aenesidemus held at the same time such opposing opinions?
[1] Adv. Math. X. 233.
[2] Adv. Math. IX. 337; X. 216.
[3] Adv. Math. X. 38.