For the enemy/friends of man are his pruners. They prevent him from destroying himself by excess fertility, so that a person who dies of malaria or tuberculosis should be honored at least as much as one who has died for his country in battle. He has made room for the rest of us, and the bacteria which killed him should be saluted with proper chivalry as an honorable foe. The point is not that we should forthwith abandon penicillin or DDT: it is that we should fight to check the enemy, not to eliminate him. We must learn to include ourselves in the round of cooperations and conflicts, of symbiosis and preying, which constitutes the balance of nature, for a permanently victorious species destroys, not only itself, but all other life in its environment.