The Divine Institutes

Zeno and the Stoics, then, were right in repudiating conjecture. For to conjecture that you know that which you do not know, is not the part of a wise, but rather of a rash and foolish man. Therefore if nothing can be known, as Socrates taught, or ought to be conjectured, as Zeno taught, philosophy is entirely removed. Why should I say that it is not only overthrown by these two, who were the chiefs of philosophy, but by all, so that it now appears to have been long ago destroyed by its own arms?

Philosophy has been divided into many sects; and they all entertain various sentiments. In which do we place the truth? It certainly cannot be in all. Let us point out some one; it follows that all the others will be without wisdom. Let us pass through them separately; in the same manner, whatever we shall give to one we shall take away from the others. For each particular sect overturns all others, to confirm itself and its own doctrines: nor does it allow wisdom to any other, lest it should confess that it is itself foolish; but as it takes away others, so is it taken away itself by all others.

For they are nevertheless philosophers who accuse it of folly. Whatever sect you shall praise and pronounce true, that is censured by philosophers as false. Shall we therefore believe one which praises itself and its doctrine, or the many which blame the ignorance of each other? That must of necessity be better which is held by great numbers, than that which is held by one only. For no one can rightly judge concerning himself, as the renowned poet testifies; for the nature of men is so arranged, that they see and distinguish the affairs of others better than their own.

Since, therefore, all things are uncertain, we must either believe all or none: if we are to believe no one, then the wise have no existence, because while they separately affirm different things they think themselves wise; if all, it is equally true that there are no wise men, because all deny the wisdom of each individually. Therefore all are in this manner destroyed; and as those fabled sparti of the poets, so these men mutually slay one another, so that no one remains of all; which happens on this account, because they have a sword, but have no shield.

If, therefore, the sects individually are convicted of folly by the judgment of many sects, it follows that all are found to be vain and empty; and thus philosophy consumes and destroys itself. And since Arcesilas the founder of the Academy understood this, he collected together the mutual censures of all, and the confession of ignorance made by distinguished philosophers, and armed himself against all. Thus he established a new philosophy of not philosophizing. From this founder, therefore, there began to be two kinds of philosophy: one the old one, which claims to itself knowledge; the other a new one, opposed to the former, and which detracts from it.

Between these two kinds of philosophy I see that there is disagreement, and as it were civil war. On which side shall we place wisdom, which cannot be torn asunder? If the nature of things can be known, this troop of recruits will perish; if it cannot, the veterans will be destroyed: if they shall be equal, nevertheless philosophy, the guide of all, will still perish, because it is divided; for nothing can be opposed to itself without its own destruction. But if, as I have shown, there can be no inner and peculiar knowledge in man on account of the frailty of the human condition, the party of Arcesilas prevails. But not even will this stand firm, because it cannot be the case that nothing at all is known.