We need not, however, for our present purpose, attempt to ascertain how the distinctively emotional characteristics arise. It is sufficient that they are presumably present in the situation. Now, as Dr. Stout well points out,[186] the emotions generally presuppose the existence of certain specific tendencies. “The anger produced in a dog by taking away its bone presupposes the specific appetite for food. The anger produced in it by interfering with its young presupposes the specific tendency to guard and tend its offspring. So the presence of a rival who interferes with its wooing causes anger because of the pre-existence of the sexual impulse.” In general, we may say that emotional states are, under natural conditions, closely associated with behaviour of biological value--with tendencies which are beneficial in self-preservation or race-preservation--with actions that promote survival, and especially with the behaviour which clusters round the pairing and parental instincts. The value of the emotions in animals is that they are an indirect means of furthering survival. But how has the close association between emotional condition and the biological end it furthers been established? Again, we must say that under natural conditions it is not the sort of thing which could be acquired. And again we must urge that natural selection through survival is, apart from some theory of pre-established harmony, the only hypothesis in the field on which the close association can be explained.