It is, therefore, to the second set of media, which may be generally characterized as scientific and practical, that we now turn.  These are the forces which apparently are most affecting Christian preaching at this moment.  But it is important to remember that a large part of their influence is to be traced to the philosophic and ethical tendencies of the earlier humanistic movement which had set the scene for them, to which they are so sympathetic that we may assert that it is in them that their practical interests are grounded and by them that their scientific methods are reinforced.  I divide this second group of media, for clearness, under three heads.

First comes the rise of the natural sciences.  In 1859, Darwin published the Origin of Species and gave to the world the evolutionary hypothesis, foreshadowed by Goethe and other eighteenth-century thinkers, simultaneously formulated by Wallace and himself.  Here is a theory, open to objections certainly, not yet conclusively demonstrated, but the most probable one which we yet possess, as to the method of the appearance and the continuance of life upon the planet.  It conceives of creation as an unimaginably long and intricate development from the inorganic to the organic, from simple to complex forms of life.  Like Kantianism and the humanistic movement generally, the evolutionary hypothesis springs from reasoned observation of man and nature, not from any a priori or speculative process.  With this theory, long a regulative idea of our world, preaching was forced to come to some sort of an understanding.  It strikes a powerful blow at the scholastic notion of a dichotomized universe divided between nature and supernature, divine and human.  It reinforced humanism by minimizing, if not making unnecessary, the objective and external source and external interpretations of religions.  It pushes back the initial creative act until it is lost in the mists and chaos of an unimaginably remote past.  Meanwhile, creative energy, the very essence of transcendent life, is, as we know it, not transcendent at all, but working outward from within, a part of the process, not above and beyond it.  The inevitable implication here is that God is sufficiently, if not exclusively, known through natural and human media.  Science recognizes Him in the terms of its own categories as in and of His world, a part of all its ongoings and developments.  But His creative life is indistinguishable from, if not identical with, its expressions.  Here, then, is a practical obliteration of the line once so sharply drawn between the natural and the supernatural.  Hence the demarcation between the divine and human into mutually exclusive states has disappeared.