Shall I show you the sinews of a philosopher? "What sinews are those?" — A will undisappointed; evils avoided; powers daily exercised, careful resolutions; unerring decisions. Discourses

“If you do not know how to love, what good is the rising and setting of the sun?” Samarkand

“The power and capacity of learning exists in the soul already; and that just as the eye was unable to turn from darkness to light without the whole body, so too the instrument of knowledge can only by the movement of the whole soul be turned from the world of becoming into that of being, and learn by degrees to endure the sight of being, and of the brightest and best of being, or in other words, of the good.” Republic

A suitable starting point from which to compare historical developments on the different continents is around 11,000 B.C. Guns, Germs And Steel