The dogma--for a dogma it remains, in spite of the confidence of Comte or of Spencer that he had made it a scientific hypothesis--has produced an important ethical principle. Consideration for posterity has throughout history operated as a motive of conduct, but feebly, occasionally, and in a very limited sense. With the doctrine of Progress it assumes, logically, a preponderating importance; for the centre of interest is transferred to the life of future generations who are to enjoy conditions of happiness denied to us, but which our labours and sufferings are to help to bring about. If the doctrine is held in an extreme fatalistic form, then our duty is to resign ourselves cheerfully to sacrifices for the sake of unknown descendants, just as ordinary altruism enjoins the cheerful acceptance of sacrifices for the sake of living fellow-creatures. Winwood Reade indicated this when he wrote, "Our own prosperity is founded on the agonies of the past. Is it therefore unjust that we also should suffer for the benefit of those who are to come?" But if it is held that each generation can by its own deliberate acts determine for good or evil the destinies of the race, then our duties towards others reach out through time as well as through space, and our contemporaries are only a negligible fraction of the "neighbours" to whom we owe obligations. The ethical end may still be formulated, with the Utilitarians, as the greatest happiness of the greatest number; only the greatest number includes, as Kidd observed, "the members of generations yet unborn or unthought of." This extension of the moral code, if it is not yet conspicuous in treatises on Ethics, has in late years been obtaining recognition in practice. 5. Within the last forty years nearly every civilised country has produced a large literature on social science, in which indefinite Progress is generally assumed as an axiom. But the "law" whose investigation Kant designated as the task for a Newton, which Saint-Simon and Comte did not find, and to which Spencer's evolutionary formula would stand in the same relation as it stands to the law of gravitation, remains still undiscovered. To examine or even glance at this literature, or to speculate how theories of Progress may be modified by recent philosophical speculation, lies beyond the scope of this volume, which is only concerned with tracing the origin of the idea and its growth up to the time when it became a current creed.