The theory of evolution is thus primarily the history of an order of sequent facts and relations. It is an account of the origin or growth of things, which attempts to explain their nature and constitution by showing how they have come to be what they are. But, in so doing, it naturally reveals the method and tendency of this order. And it is by means of this its teleological aspect that we see how it may be possible for it not merely to trace the development of historical facts, such as the feelings and customs of men, but at the same time to make a more real contribution to ethics by pointing out the course of action to which human nature is adapted. It does not, like the old teleology, attempt to show that each thing has been formed with the design of subserving some particular purpose. On the contrary, it reverses this way of looking at things. The fitness of an organism to fulfil any definite end comes to be regarded as the result not of a conscious design, independent of the environment, but of the modifications produced on the organism through the necessity laid upon it by its surroundings of adapting itself to them or else disappearing. What the theory does show is, that adaptation to environment is necessary for life, and that organisms unable to adapt themselves pass away. Adaptation to environment will thus be implied in, or be an essential means towards, self-preservation and race-preservation, self-development and race-development. And should this preservation or development be looked upon as the end of conduct, the adaptation to environment it implies may help to define and characterise the end.