I recall that Huxley said that there was a third reality in this universe besides matter and energy, and this third reality was consciousness. But neither the "_x_-entity" of Professor Ganong nor the "consciousness" of Huxley can be said to be of the same cosmic rank as matter and energy, because they do not pervade the universe as matter and energy do. These forces abound throughout all space and endure throughout all time, but life and consciousness are flitting and uncertain phenomena of matter. A prick of a pin, or a blow from a hammer, may destroy both. Unless we consider them as potential in all matter (and who shall say that they are not?) may we look upon them as of cosmic rank? It is often urged that it is not the eye that sees, or the brain that thinks, but something in them. But it is something in them that never went into them; it arose in them. It is the living eye and the living brain that do the seeing and the thinking. When the life activity ceases, these organs cease to see and to think. Their activity is kept up by certain physiological processes in the organs of the body, and to ask what keeps up these is like the puppy trying to overtake its own tail, or to run a race with its own shadow. The brain is not merely the organ of the mind in an external and mechanical sense; it is the mind. When we come to living things, all such analogies fail us. Life is not a thing; thought is not a thing; but rather the effect of a certain activity in matter, which mind alone can recognize. When we try to explain or account for that which we are, it is as if a man were trying to lift himself. Life seems like something apart. It does not seem to be amenable to the law of the correlation and conservation of forces. You cannot transform it into heat or light or electricity. The force which a man extracts from the food he eats while he is writing a poem, or doing any other mental work, seems lost to the universe. The force which the engine, or any machine, uses up, reappears as work done, or as heat or light or some other physical manifestation. But the energy of foodstuffs which a man uses up in a mental effort does not appear again in the circuit of the law of the conservation of energy. A man uses up more energy in his waking moments, though his body be passive, than in his sleeping. What we call mental force cannot be accounted for in terms of physical force. The sun's energy goes into our bodies through the food we eat, and so runs our mental faculties, but how does it get back again into the physical realm? Science does not know.