If we look upon life as inherent or potential in the constitution of matter, dependent upon outward physical and chemical conditions for its development, we are accounting for life in terms of matter and motion, and are in the ranks of the materialists. But if we find ourselves unable to set the ultimate particles of matter in action, or so working as to produce the reaction which results in life, without conceiving of some new force or principle operating upon them, then we are in the ranks of the vitalists or idealists. The idealists see the original atoms slumbering there in rock and sea and soil for untold ages, till, moved upon by some unknown factor, they draw together in certain fixed order and numbers, and life is the result. Something seems to put a spell upon them and cause them to behave so differently from the way they behaved before they were drawn into the life circuit. When we think of life, as the materialists do, as of mechanico-chemical origin, or explicable in terms of the natural universal order, we think of the play of material forces amid which we live, we think of their subtle action and interaction all about us--of osmosis, capillarity, radio-activity, electricity, thermism, and the like; we think of the four states of matter,--solid, fluid, gaseous, and ethereal,--of how little our senses take in of their total activities, and we do not feel the need of invoking a transcendental principle to account for it. Yet to fail to see that what we must call intelligence pervades and is active in all organic nature is to be spiritually blind. But to see it as something foreign to, or separable from, nature is to do violence to our faith in the constancy and sufficiency of the natural order. One star differeth from another star in glory. There are degrees of mystery in the universe. The most mysterious thing in inorganic nature is electricity--that disembodied energy that slumbers in the ultimate particles of matter--unseen, unfelt, unknown, till it suddenly leaps forth with such terrible vividness and power on the face of the storm, or till we summon it through the transformation of some other form of energy. A still higher and more inscrutable mystery is life--that something which clothes itself in such infinitely varied and beautiful as well as unbeautiful forms of matter. We can evoke electricity at will from many different sources, but we can evoke life only from other life; the biogenetic law is inviolable. IV