These are the two simplest possible reactions with sense of the experienceable injurious. In fear there is elimination of oneself from the injury, and in anger the elimination of the injury from oneself. With later anger and fear these processes of elimination themselves become matters of representation, and make a large part in highly-developed forms. A knowledge which very generally enters into anger is the comparative estimate of power. A cat scratches us, we are angry; a lion threatens us, we are afraid. The progress of the lower psychic life is largely in learning what is best to fear and what should excite anger. That which at first angers will often, when better understood, produce fear, and _vice versâ_. Wild animals at first often show merely anger when molested by man, but soon manifest fear as they learn to appreciate his superior power. The African elephant learns to distinguish between the savage with his spear, and the white hunter with his rifle, and is merely irritated or angry with the one, while he manifests genuine fear of the other. The young of animals and of man continually show irrelevant fear and anger. They are generally either over fearful or over irritable. Our own feelings are powerfully modified by varying estimates of opposing force and injury. If, in passing through a dark street, I am tripped by what I take to be a child’s snare, I am angered, but upon noticing that it is a fuse to a dynamite bomb, I am thrown into intense fear. In general, any sensation, as of sound or light, in its lower grades of intensity produces anger, in higher occasions fear. As a rule when reactions induced by either fear or anger are uniformly unsuccessful, natural selection favours the development of the other. While the comparative estimate of opposing force with one’s own is general ingredient in anger, anger being fear-limited, it is not, as Mercier would indicate (_Mind_, ix., p. 346), a constant element in anger. We often see cases of anger, and have perhaps, ourselves, experienced anger which is totally unrelated to a sense of power. Some animals seem at times utterly fearless and utterly unaware of the tremendous crushing force they angrily oppose. It is, moreover, altogether probable that anger and fear originated and received a certain measure of development before any capacity of measuring comparative force of antagonist arose in mind. However, the discrimination between overwhelming and slight force is certainly tolerably early, and is obviously a very necessary factor in self-conservative action. Yet it is very unlikely that this was an element in primitive fear or anger, which must have been no more than a simple emotional reaction to perceived injury without any reference to whether pain-giver is more or less strong than pain-receiver. The earliest fears and angers of infants seem to be quite devoid of any guidance from sense of powerlessness or power, but merely direct, unthinking reactions.