We must, if we are to be consistent, and if we re to have a real pedigree herd, mate the best of our men with the best of our women as often as possible, and the inferior men with the inferior women as seldom as possible, and keep only the offspring of the best.
PlatoThe mortal nature is seeking as far as is possible to be everlasting and immortal: and this is only to be attained by generation, because the new is always left in the place of the old.
Plato