Life, then, in all its forms is for its own sake. It is an end in itself. Many things are inimical to us, and we are equally inimical to many things. We lay the whole of Nature under contribution so far as we can, and we curb and defeat her hostile forces so far as we can, but the world was no more made for man than it was made for mice and midges. When we see how irrespective of us the natural forces go their way, that we can ride them and guide them only as we do wild horses--by being quicker and more masterful than they are--when we know that they will tread us down with the same indifference that we tread down the grass and the weeds, the facts should temper and modify our egotism. When we look into the depths of merely our own solar system, and see vast globes like Jupiter and Saturn, so much older and greater than our little earth, and not yet the abode of any form of life, and probably not within millions of years of such a state, how casual and insignificant man seems! How far from being the end and object of creation! Doubtless there are numberless worlds and whole systems of worlds in the depths of sidereal space upon which life has never appeared, and numberless other worlds and systems upon which it has had its day and gone out forever. Life is but an incident in the total scheme of things. To ask what this or that is for, with reference to ourselves, and to conclude that some one or something has blundered if it is not of positive use to us, is, let me repeat, to see and to think as a child. We know what the hooks on the burdock and the stick-seed are for, and what the wings on the maple and the ash-seed are for, but do we know what the stings on the nettle, or the spines on the blackberry or on the thorn-apple tree are for? The cattle eat the nettle, the birds eat the berries, and the wild creatures eat the thorn-apple. How could their seeds get sown if the prickles and thorns defended them against wild life? Spines and thorns seem expressive of moods or conditions in Nature, and to be quite independent of use, as we understand the term.