I see that it is a machine in this respect, that it is set going by a force exterior to itself--the warmth of the sun acting upon it, and upon the moisture in the soil; but it is unmechanical in that it repairs itself and grows and reproduces itself, and after it has ceased running can never be made to run again. After I have reduced all its activities to mechanical and chemical principles, my mind seems to see something that chemistry and mechanics do not explain--something that avails itself of these forces, but is not of them. This may be only my anthropomorphic way of looking at things, but are not all our ways of looking at things anthropomorphic? How can they be any other? They cannot be deific since we are not gods. They may be scientific. But what is science but a kind of anthropomorphism? Kant wisely said, "It sounds at first singular, but is none the less certain, that the understanding does not derive its laws from nature, but prescribes them to nature." This is the anthropomorphism of science. If I attribute the phenomenon of life to a vital force or principle, am I any more unscientific than I am when I give a local habitation and a name to any other causal force, as gravity, chemical affinity, cohesion, osmosis, electricity, and so forth? These terms stand for certain special activities in nature and are as much the inventions of our own minds as are any of the rest of our ideas. We can help ourselves out, as Haeckel does, by calling the physical forces--such as the magnet that attracts the iron filings, the powder that explodes, the steam that drives the locomotive, and the like--"living inorganics," and looking upon them as acting by "living force as much as the sensitive mimosa does when it contracts its leaves at touch." But living force is what we are trying to differentiate from mechanical force, and what do we gain by confounding the two? We can only look upon a living body as a machine by forming new conceptions of a machine--a machine utterly unmechanical, which is a contradiction of terms. A man may expend the same kind of force in thinking that he expends in chopping his wood, but that fact does not put the two kinds of activity on the same level. There is no question but that the food consumed is the source of the energy in both cases, but in the one the energy is muscular, and in the other it is nervous. When we speak of mental or spiritual force, we have as distinct a conception as when we speak of physical force. It requires physical force to produce the effect that we call mental force, though how the one can result in the other is past understanding. The law of the correlation and conservation of energy requires that what goes into the body as physical force must come out in some form of physical force--heat, light, electricity, and so forth.