"By the renunciation of all pleasure, and of all reward by seeking God only, with unshaken faith, we reach the sun which has no end, the great world, whence we return no more to a world which is the recompense of evil."[20] The Egyptians, having borrowed this doctrine from the Hindoos, made it the basis of their religious worship. Herodotus informs us,[21] that, according to the Egyptians, the human soul, on issuing from a completely decomposed body, enters into that of some animal. The soul takes three thousand years to pass from this body through a series of others, and at the conclusion of this interval, the same soul returns to the human species, entering the form of a newly-born infant. The Egyptians employed excessive caution in the preservation of human bodies. They embalmed the corpses of their relatives or of personages of importance to the state, and thus prepared the mummies which are to be seen in all our museums. The universal practice of embalming was not intended, as has been supposed, to keep the human body ready to receive the soul, returning at the end of three thousand years, to seek its primitive abode. It had another object. It was supposed that the soul did not commence its migrations after the death of the human body, while any portion of the corpse remained entire. Hence the efforts made by the Egyptians, to retard the moment of separation by the preservation of the corpse as long as possible. Servius says: "The Egyptians, renowned for their wisdom, prolonged the duration of corpses, that the existence of the soul, attached to that of the body, might be preserved, and might not pass away quickly to others. The Romans, on the contrary, burn corpses, so that the soul, resuming its liberty, might immediately re-enter nature." The most ancient and remarkable of the Greek philosophers, Pythagoras, found out the doctrine of the metempsychosis, in his travels in Egypt. He adopted it in his school, and the whole of the Greek philosophy held, with Pythagoras, that the souls of the wicked pass into the bodies of animals. Hence the abstinence from flesh meat, prescribed by Pythagoras to his disciples, a precept which he also derived from Egypt, where respect for animals was due to the general persuasion that the bodies of beasts were tenanted by human souls, and, consequently, that by ill-treating animals, one ran the risk of injuring one's own ancestors. Empedocles, the philosopher, adopted the Pythagorean system. He says, in lines quoted by Clement of Alexandria:-- "I, too, have been a young maiden, A tree, a bird, a mute fish in the seas."