Some, for instance, say that there cannot be several originating causes for one animal. It is impossible that there can be several homogeneous originating causes of an animal; but that there should be several heterogeneous, is not absurd.
Suppose the Pyrrhonian suspense of judgment, as they say, [the idea] that nothing is certain: it is plain that, beginning with itself, it first invalidates itself. It either grants that something is true, that you are not to suspend your judgment on all things; or it persists in saying that there is nothing true. And it is evident, that first it will not be true. For it either affirms what is true or it does not affirm what is true. But if it affirms what is true, it concedes, though unwillingly, that something is true. And if it does not affirm what is true, it leaves true what it wished to do away with. For, in so far as the scepticism which demolishes is proved false, in so far the positions which are being demolished, are proved true; like the dream which says that all dreams are false. For in confuting itself, it is confirmatory of the others.
And, in fine, if it is true, it will make a beginning with itself, and not be scepticism of anything else but of itself first. Then if [such a man] apprehends that he is a man, or that he is sceptical, it is evident that he is not sceptical. 3708 And how shall he reply to the interrogation? For he is evidently no sceptic in respect to this. Nay, he affirms even that he does doubt.
And if this position is true, that we do not know what is true, then absolutely nothing is allowed to be true by it. But if he will say that even this is questionable, whether we know what is true; by this very statement he grants that truth is knowable, in the very act of appearing to establish the doubt respecting it.
But if a philosophical sect is a leaning toward dogmas, or, according to some, a leaning to a number of dogmas which have consistency with one another and with phenomena, tending to a right life; and dogma is a logical conception, and conception is a state and assent of the mind: not merely sceptics, but every one who dogmatizes is accustomed in certain things to suspend his judgment, either through want of strength of mind, or want of clearness in the things, or equal force in the reasons.