In a world of absolute zero everything would be as solid as the rocks, all life, all chemical reactions would cease. All forms of water are the result of more or less heat. The circuit of the waters from the earth to the clouds and back again, which keeps all the machinery of life a-going, is the work of varying degrees of temperature. The Gulf Stream, which plays such a part in the climate of Europe, is the result of the heat in the Gulf of Mexico. The glacial periods which have so modified the surface of the earth in the past were the result of temperature changes. * * * * * How habitually we speak of beauty as a positive thing, just as we do of truth! whereas what we call beauty is only an emotional experience of our own minds, just as light and heat are sensations of our bodies. There is no light where there is no eye, and no sound where there is no ear. One is a vibration in the ether, and the other a vibration in the air. The vibrations are positive. We do not all see beauty in the same things. One man is unmoved where another is thrilled. We say the world is full of beauty, when we mean that it is full of objects that excite this emotion in our minds. We speak of truth as if it, too, were a positive thing, and as if there were a fixed quantity of it in the world, as there is of gold or silver, or diamonds. Truth, again, is an intellectual emotion of the human mind. One man's truth is another man's falsehood--moral and aesthetic truth, I mean. Objective truth (mathematics and science) must be the same to all men. A certain mode of motion in the molecules of matter gives us the sensation of heat, but heat is not a thing, an entity in itself, any more than cold is. Yet to our senses one seems just as positive as the other. New truth means a new man. There are as many kinds of truth as there are human experiences and temperaments. * * * * * How adaptive is animal life! It adds a new touch of interest to the forbidding cactus to know that the cactus wren builds her nest between its leaves. The spines probably serve to protect the bird from her enemies. But are they not also a menace to her and to her young? But this "procreant cradle" of a bird in the arms of the fanged desert growth softens its aspect a little. * * * * *