In an ethical system founded upon an acceptance of biological and sociological evolution, all these systems of previous philosophers find a due place. Egoism cannot be denied as the rule of life, but it is shown that egoism cannot always remain purely egoistic, but at last includes inevitably an altruistic growth. The progress of society involves altruistic conditions. The intrinsic growth of sympathy and the extrinsic imposition of conditions form in a continuous society, by change in the internal constitution of organisms, and by hereditary transmission of such changes, not only an intuitional feeling of right and wrong, but also an intuitional conscience of greater or less development. Thus, we admit and explain the law of right and wrong written upon each civilized human heart. Utilitarianism is recognised as the ultimate outcome of philosophical thought; and, while it is but an inadequate expression in the hands of some writers, it may, perhaps, in its wider expansion by later philosophers, become an adequate and suitable expression of the ethical principle, and a guide for re-adjustments in the recognition of the wider ends and larger views of human organisation. But any one of these views is inadequate by itself to explain and express the largeness of ethical movement. Only when we seize upon the history of the development of subjectivity, only when we understand the gradual progress from gross beginnings, and recognise the grand movement which carries us forward to we know not what hopeful future, can we properly appreciate the ethical position and the ethical authority. But to one who understands the evolution of organisms and of society, all these varying views fall at once into their natural places in a beautiful harmony. The touch of genius in a Darwin or a Spencer, produces out of the apparent chaos a well-ordered and progressive system. This is the proper place to notice Mr. Leslie Stephen's very valuable and elaborate work upon "The Science of Ethics." That work is wise in conception, sound as to its basis and construction, beautifully proportioned in its mode of treatment, carefully, and, perhaps, too elaborately worked out in detail. The original conception is wise in that it excludes metaphysical questions and discussions as to first principles, and limits the range of its considerations to properly-ascertained scientific facts or laws, and to such extensions of scientific surmise as are warranted by the acceptance of the modern doctrine of evolution, expounded by Darwin. The acceptance of this doctrine not only involves the acceptance of historic developments, but justifies, and even necessitates, the acceptance of a supposititious prehistoric development. This hypothetical history, founded on observations of historical order, and of the habits and customs of uncivilised races, is perfectly justifiable. However, the problem, conducted within scientific limits is to consider the groundwork of actual morality (Ch. i.).