Everyone, including the Athenians [...] are right to accept advice from anyone, since it is incumbent on everyone to share in that sort of excellence, or else there can be no city at all.

Many things prevent knowledge, including the obscurity of the subject and the brevity of human life

There are two sides to every question.

Man is the measure of all things, of the reality of those which are, and of the unreality of those which are not.

About the gods I have no means of knowing either that they exist or that they do not exist or what they are to look at. Many things prevent my knowing. Among others, the fact that they are never seen.

Man is the measure of all things, of things that are that they are, and of things that are not that they are not.

There are intelligible principles inherent in the matter of every phenomenon; because matter is essentially the sum of all the seemings that it has for any and all persons.