text: I have been speaking so far of liberal studies; but think how much superfluous and unpractical matter the philosophers contain! Of their own accord they also have descended to establishing nice divisions of syllables, to determining the true meaning of conjunctions and prepositions; they have been envious of the scholars, envious of the mathematicians. They have taken over into their own art all the superfluities of these other arts; the result is that they know more about careful speaking than about careful living. Let me tell you what evils are due to over-nice exactness, and what an enemy it is of truth! Protagoras declares that one can take either side on any question and debate it with equal success – even on this very question, whether every subject can be debated from either point of view. Nausiphanes holds that in things which seem to exist, there is no difference between existence and non-existence. Parmenides maintains that nothing exists of all this which seems to exist, except the universe alone. Zeno of Elea removed all the difficulties by removing one; for he declares that nothing exists. The Pyrrhonean, Megarian, Eretrian, and Academic schools are all engaged in practically the same task; they have introduced a new knowledge, non-knowledge. You may sweep all these theories in with the superfluous troops of "liberal" studies; the one class of men give me a knowledge that will be of no use to me, the other class do away with any hope of attaining knowledge. It is better, of course, to know useless things than to know nothing. One set of philosophers offers no light by which I may direct my gaze toward the truth; the other digs out my very eyes and leaves me blind. If I cleave to Protagoras, there is nothing in the scheme of nature that is not doubtful; if I hold with Nausiphanes, I am sure only of this – that everything is unsure; if with Parmenides, there is nothing except the One; if with Zeno, there is not even the One.