Lives and Opinions of Eminent Philosophers

​Concerning those who thought that one ought not to judge truth from circumstantial conditions nor lay down rules from what is natural, they used to say that they themselves define the measures of all things, not seeing that everything that appears, appears in accordance with counter-circumstance and disposition. Either, at any rate, all things must be said to be true, or all things false. But if some things are true, by what are they to be distinguished? For things according to sense cannot be distinguished by sense, since all things appear equal to it, nor by thought for the same reason; and no other faculty is seen beside these for the purpose of decision. He, therefore, they say, who makes an assertion about something sensible or intelligible must first establish the opinions concerning it; for some have abolished these, and others those. And it must be judged either through a sensible or an intelligible thing; but both are in dispute.

​It is not possible, therefore, to decide the opinions concerning sensible or intelligible things. And if, because of the conflict in thoughts, all things must be distrusted, the measure by which all things seem to be accurately distinguished will be done away with; they will, therefore, consider everything equal. Furthermore, they say, is the person who investigates the appearance with us credible or not? If, on the one hand, he is credible, he will have nothing to say against the one to whom the opposite appears; for just as he is credible in stating his appearance, so also is the opponent. If, on the other hand, he is not credible, he himself will also be distrusted when stating his appearance.

​Nor must that which persuades be assumed to exist as true; for the same thing does not persuade everyone, nor the same people continuously. Persuasiveness also arises from external circumstances: from the repute of the speaker, or from diligence, or from shrewdness, or from familiarity, or from pleasingness. They used to abolish the criterion as well by such an argument as this. Either the criterion itself has also been judged, or it is unjudged. But if it is unjudged, it has become untrustworthy and misses both the truth and falsehood; whereas if it has been judged, it will become one of the particular things that are judged, so that the same thing would both judge and be judged, and that which judged the criterion will be judged by another, and that by another, and so to infinity.

​In addition to this, the criterion is also disputed, some saying that man is the criterion, some the senses, others reason, and some the cognitive impression. And man is in disagreement both with himself and with others, as is clear from differing laws and customs; the senses deceive, and reason is in conflict; the cognitive impression is judged by the intellect, and the intellect changes in various ways. The criterion, therefore, is unknown, and through this, so is truth.

​Moreover, they held that a sign does not exist. For if a sign exists, they say, it is either sensible or intelligible. It is not sensible, since the sensible is common, while the sign is proper; and the sensible belongs to things categorized by difference, while the sign belongs to relative things. Nor is it intelligible, since the intelligible sign is either an apparent sign of an apparent thing, or a non-evident of a non-evident, or a non-evident of an apparent, or an apparent of a non-evident. But it is none of these; therefore, there is no sign. It is not an apparent sign of an apparent thing, since that which is apparent needs no sign; nor is it a non-evident sign of a non-evident thing, since that which is disclosed by something must be apparent;

​nor can it be a non-evident sign of an apparent thing, because that which is to furnish another with the starting point of apprehension must be apparent; nor is it an apparent sign of a non-evident thing, because the sign, being among relative things, ought to be apprehended together with that of which it is a sign, but this is not the case. Therefore, none of the non-evident things could be apprehended; for it is through signs that non-evident things are said to be apprehended. And they abolish the cause in this way: the cause belongs to relative things, for it is relative to the effect; but relative things are only conceived in thought, and do not exist in reality.