Every individual, whatever its species or order, begins and increases until it attains to its state of fullest development, under certain fixed laws, and _in consequence_ of their operation. The microscopic monad develops into a fœtus, the fœtus into a child, the child into a man; and, however marvellous the process, in none of its stages is there the slightest mixture of miracle; from beginning to end, all is progressive development, according to a determinate order of things. Has _Nature_, during the vast geologic periods, been pregnant, in like manner, with the human race? and is the species, like the individual, an effect of progressive development, induced and regulated by law? The assertors of the revived hypothesis of Maillet and Lamarck reply in the affirmative. Nor, be it remarked, is there positive atheism involved in the belief. God might as certainly have _originated_ the species by a law of development, as he _maintains_ it by a law of development; the existence of a First Great Cause is as perfectly compatible with the one scheme as with the other; and it may be necessary thus broadly to state the fact, not only in justice to the Lamarckians, but also fairly to warn their non-geological opponents, that in this contest the old anti-atheistic arguments, whether founded on the evidence of design, or on the preliminary doctrine of final causes, cannot be brought to bear. There are, however, beliefs, in no degree less important to the moralist or the Christian than even that in the being of a God, which seem wholly incompatible with the development hypothesis. It, during a period so vast as to be scarce expressible by figures, the creatures now human have been rising, by _almost_ infinitesimals, from compound microscopic cells,—minute vital globules within globules, begot by electricity on dead gelatinous matter,—until they have at length become the men and women whom we see around us, we must hold either the monstrous belief, that all the vitalities, whether those of monads or of mites, of fishes or of reptiles, of birds or of beasts, are individually and inherently immortal and undying, or that human souls are _not_ so. The difference between the dying and the undying,—between the spirit of the brute that goeth downward, and the spirit of the man that goeth upward,—is not a difference infinitesimally, or even atomically _small_. It possesses all the breadth of the eternity to come, and is an _infinitely great_ difference. It cannot, if I may so express myself, be shaded off by infinitesimals or atoms; for it is a difference which—as there can be no class of beings intermediate in their nature between the dying and the undying—admits not of gradation at all. What mind, regulated by the ordinary principles of human belief, can possibly hold that every one of the thousand vital points which swim in a drop of stagnant water are inherently fitted to maintain their individuality throughout eternity? Or