3. For we come into the world having by nature no idea of a right-angled triangle, or a quarter-tone, or a semi-tone, but by a certain tradition of art we learn each of these things. And thus those who know them not, do not suppose that they know them. But good and evil, and nobleness and baseness, and the seemly and the unseemly, and happiness and misfortune, and what is our concern and what is not, and what ought to be done and what not—who hath come into the world without an implanted notion of these things? Thus we all use these terms, and endeavor to fit our natural conceptions to every several thing. _He did well, rightly, not rightly, he failed, he succeeded, he is unrighteous, he is righteous_—which of us spareth to use terms like these? Which of us will defer the use of them till he hath learned them, even as ignorant men do not use terms of geometry or music? But this is the reason of it: we come into the world already, as it were, taught by Nature some things in this kind, and setting out from these things we have added thereto our own conceit.[2] _For how_, saith one, _do I not know what is noble and what is base_? Have I not the notion of it? Truly. _And do I not apply it to things severally?_ You do apply it. _Do I not, then, apply it rightly?_ But here lies the whole question, and here conceit entereth in. For setting out from things confessed by all, they go on by a false application to that which is disputed. For if, in addition to those things, they had gained also this power of application, what would then hinder them to be perfect? But now since you think that you apply rightly the natural conceptions to things severally, tell me, whence have you this assurance? ——“Because it seems so to me.” But to another it seems otherwise—and he, too, doth he think his application right or not? ——“He doth think it.” Can ye, then, both be rightly applying the conceptions in matters wherein your opinions contradict each other? ——“We cannot.” Have you, then, aught better to show for your application, or aught above this, that it seemeth so to you? But what else doth a madman do than those things that to him seem right? And doth this rule suffice for him? ——“It doth not suffice.” Come, then, to that which is above seeming. What is this? 4. Behold, the beginning of philosophy is the observation of how men contradict each other, and the search whence cometh this contradiction, and the censure and mistrust of bare opinion. And it is an inquiry into that which seems, whether it rightly seems; and the discovery of a certain rule, even as we have found a balance for weights, and a plumb line for straight and crooked. This is the beginning of philosophy. Are all things right to all to whom they seem so? But how can contradictory things be right? ——“Nay, then, not all things, but those that seem to us right.”