Nor had Plato less of probability to support his theory than Darwin had to support his. The Greek philosopher might have adduced the constant spectacle of men debasing their habits and even their physical appearance into a resemblance to the brutes. He might have suggested, and he does suggest, how the degrading tendencies of the lower appetites and the ravages of disease drag down the human frame from its erect carriage and its commanding power over matter to an approximation with the condition of the inferior animals. He might have adduced innumerable proofs of the loss of reason, or rationality, through successive generations of men, brought about by the transmission of both appetites and physical malformation from parents to children. He might have compared one of his Athenian fellow-citizens of the higher class with the lowest savage known throughout all the regions accessible to an observer of his day and country. He might have portrayed the one as a being preserving his physical organization in the highest state of perfection by gymnastic exercises, by a well-chosen diet, by observance of all the conditions of health, by the aid of the highest medical skill known to the age; cultivating his mind by philosophy, practicing every public and private virtue as they were understood among a people of rare refinement, and adorning his race by an exhibition of the highest qualities that were then attainable. All these qualities, physical, mental, and moral, Plato might have shown were transmissible in some degree, and in a good degree were actually transmitted from sire to son. Turning to the other picture, and comparing "Hyperion to the satyr," he might have shown that the lowest savage, in those physical points of structure which were best adapted to his animal preservation as an inhabitant of the wildest portion of the earth, had retained those which made him more nearly resemble the brute inhabitants of the same region, and that in his intellectual and moral qualities the resemblance between him and his Athenian contemporary was almost wholly lost. Intermediate between these extreme specimens of the human race, why could not Plato have found with great probability, and often with actual proof, successive degradations of structure and uses of organs, just as well supported by facts, or analogies, or hypotheses, as are Mr. Darwin's successive elevations from a lower to a higher animal? If Plato had known as much about the animal kingdom as is now known, he could have arrayed the same facts in support of his theory, by an argument as powerful as that which now supports the doctrine of evolution.