Goethe said to Eckermann that he followed Kant in looking upon each creature as existing for its own sake. He could not believe, he said, that the cork-trees grow merely that we might stop our bottles, and, he might have added, that rubber-trees grow that we might have rubber overshoes. The lady in a public audience who once asked me what flies are for, evidently thought that God had made a mistake in creating that which annoyed her. I was pleased with a remark of John Muir’s in his Sierra book about the poison-ivy: “Like most other things not apparently useful to man,” he says, “it has few friends, and the blind question, ‘Why was it made?’ goes on and on with never a guess that first of all it might have been made for itself.” Coming from the mouth of a Scotch Presbyterian, this is heretical doctrine. Muir had evidently forgotten his early training. It is possible for man to make use of poison-ivy; in fact it is used in medicine; but who shall dare to say that it was made for that? Flies and poison ivy and all other noxious and harmful things are each and all for their own sakes. They were not made in the sense that we make things. They have come to be what we now find them through the action and interaction of a thousand complex influences. Each has found its place in the scheme of living things, and each acts directly or indirectly upon other forms--is of use to them, or the reverse. Ten thousand things are of use to man, and as many more of no use to him, but to measure all things by his standard of utility is childish, or to ask what mosquitoes and rattlesnakes are for, with an implied impeachment of Nature if they are not of service to man, is an idle question. The water and the air are indispensable to life, but these things are older than life. Life is adapted to them, and not they to it. The body is full of fluids because earth and air are full of water. From our standpoint man is at the head of animate nature, but the rest of creation is no more exclusively for him than for the least of living things. The good of the world is for whatever or whoever can use it. Houseflies are undoubtedly the enemy of the human race; so are mosquitoes, so are venomous snakes, so are many forms of bacteria, and a thousand other things. Our egotism prompts us to ask, “Why is evil in the world, anyhow?” But our evil may be the good of some other creature. Our defeat means the triumph of our enemy. It is through this conflict of good and evil, or of things that are for us with things that are against us, that species are developed and perpetuated.