While Morel practically outlined the modern study of degeneracy, his theologic timidity forced an absolute definition of a state which, according to his own admission, was purely relative. After fencing somewhat with the position that there was a primevally perfect man,[9] he admits with Tessier the primeval lowness of man, but also thinks that the fall of man could create new conditions which, in his descendants, from heredity and from causes acting on their health, tended to make them depart from the primitive type. These departures from the primitive type have led to varieties, some of which constitute races capable of transmitting racial characteristics. Other varieties in the races themselves have created the abnormal states which Morel has denominated degeneracies. Each of these degeneracies has its own stamp from the cause that produces it. Their common characteristic is hereditary transmission under graver conditions than normal heredity. With certain exceptional instances of regeneration, the progeny of degenerates presents progressive degradation. This may reach such limits that humanity is preserved by its excess. It is not necessary, however, that the ultimate stage of degradation be reached before sterility occurs. Morel confines degeneracy to a pathologic type, criticising F. Heusinger[10] for applying the term degenerate to domestic animals which "throw back" to the wild or original type. Morel's admission that causes influencing health produce deviations which, under favouring conditions, become racial types capable of indefinite transmission, saves him from absolute scientific inaccuracy, but renders inconsistent his limitation of degeneracy. It may be convenient to separate diseased states from anomalies, but such separation can only be very relative. From his conservatism and his plentiful data, Morel aroused much less antagonism than did a contemporary, Moreau (de Tours), who bore to him the relation of Darwin to Wallace.[11] While Moreau devotes much attention to the factors of degeneracy and its stigmata (or marks), like Morel, his main point is the expansion of the theory of Aristotle which Dryden epigrammatised into-- "Great wit to madness nearly is allied, And thin partitions do their bounds divide."