One more method of treating the inquiry before us will complete the list. It is what we may properly call the scientific theory, though in truth it is hardly a theory at all, but rather a careful statement of the observed facts, and a modest confession of inability to explain the cause of them. Those occupying this position, when asked what is the origin of souls, do not pretend to unveil the final secret, but simply say, everywhere in the world of life, from bottom to top, there is an organic growth in accordance with conditions. This is what is styled the theory of epigenesis, and is adopted by the chief physiologists of the present day. Swammerdam, Malebranche, even Cuvier, had defended the doctrine of successive inclusion; but Wolf, Blumenbach, and Von Baer established in its place the doctrine of epigenesis. 10 9 Leibnitz, Monadologie. 10 Ennemoser, Historisch psychologische Untersuchungen tiber den Ursprung der menschlichen Seelen, zweite Auflage. Scrupulously confining themselves to the mass of collected facts and the course of scrutinized phenomena, they say there is a natural production of new living beings in conformity to certain laws, and give an exposition of the fixed conditions and sequences of this production. Here they humbly stop, acknowledging that the causal root of power, which produces all these consequences, is an inexplicable mystery. Their attitude is well represented by Swedenborg when he says, in reference to this very subject, "Any one may form guesses; but let no son of earth pretend to penetrate the mysteries of creation." 11 Let us notice now the facts submitted to us. First, at the base of the various departments of nature, we see a mass of apparently lifeless matter. Out of this crude substratum of the outward world we observe a vast variety of organized forms produced by a variously named but unknown Power. They spring in regular methods, in determinate shapes, exist on successive stages of rank, with more or less striking demarcations of endowment, and finally fall back again, as to their physical constituents, into the inorganic stuff from which they grew. This mysterious organizing Power, pushing its animate and builded receptacles up to the level of vegetation, creates the world of plants. "Every clod feels a stir of might, An instinct within it that reaches and towers, And, grasping blindly above it for light, Climbs to a soul in grass and flowers."