Discourses, "On the Same" (§4)

“This was the practice of Socrates; this was the reason why he always had one face. But we choose to practise and study anything rather than the means by which we shall be unimpeded and free. You say: “Philosophers talk paradoxes.” But are there no paradoxes in the other arts? And what is more paradoxical than to puncture a man’s eye in order that he may see? If any one said this to a man ignorant of the surgical art, would he not ridicule the speaker? Where is the wonder, then, if in philosophy also many things which are true appear paradoxical to the inexperienced?”