Aristotle (384-322 B. C. E) Now what is characteristic of any nature is that which is best for it and gives most joy. Such a man is the life according to reason, since it is that which makes him man. There is nothing strange in the circle being the origin of any and every marvel. The so-called Pythagoreans, who were the first to take up mathematics, not only advanced this subject, but saturated with it, they fancied that the principles of mathematics were the principles of all things. To Thales the primary question was not what do we know, but how do we know it. If this is a straight line [showing his audience a straight line drawn by a ruler], then it necessarily ensues that the sum of the angles of the triangle is equal to two right angles, and conversely, if the sum is not equal to two right angles, then neither is the triangle rectilinear. It is not once nor twice but times without number that the same ideas make their appearance in the world. But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end. We cannot ... prove geometrical truths by arithmetic. The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree. The continuum is that which is divisible into indivisibles that are infinitely divisible. Physics.