Sextus Empiricus Pyrrhoniae Hypotyposes 3.5.23

[23] And even were one to grant that Cause can be conceived, it might be held to be inapprehensible because of the divergency of opinion. For he who says that there is some Cause of something either asserts that he makes this statement absolutely and without basing it on any rational cause, or else he will declare that he has arrived at his conviction owing to certain causes. ¹ If, then, he says that he states it ‟absolutely,” he will be no more worthy of credence than the man who asserts ‟absolutely” that nothing is a cause of anything; whereas if he shall mention causes on account of which he holds that something causes something, he will be attempting to support the matter in question by means of that matter itself; for when we are examining the question whether anything is the Cause of anything, he asserts that Cause exists since there exists a cause for the existence of Cause.