life, effecting for the final state of humanity what the theological synthesis effected for its primitive state. For this purpose Abstract philosophy is undoubtedly sufficient; so that even supposing that Concrete philosophy should never become so perfect as we desire, social regeneration will still be possible. [In my Theory of Development, the required Synthesis of Abstract conceptions already exists] Regarded under this more simple aspect, our system of scientific knowledge is already so far elaborated, that all thinkers whose nature is sufficiently sympathetic may proceed without delay to the problem of moral regeneration; a problem which must prepare the way for that of political reorganization. For we shall find that the theory of development of which we have been speaking, when looked at from another point of view, condenses and systematizes all our abstract conceptions of the order of nature. This will be understood by regarding all departments of our knowledge as being really component parts of one and the same science; the science of Humanity. All other sciences are but the prelude or the development of this. Before we can enter upon it directly, there are two subjects which it is necessary to investigate; our external circumstances, and the organization of our own nature. Social life cannot be understood without first understanding the medium in which it is developed, and the beings who manifest it. We shall make no progress, therefore, in the final science until we have sufficient abstract knowledge of the outer world and of individual life to define the influence of these laws on the special laws of social phenomena. And this is necessary from the logical as well as from the scientific point of view. The feeble faculties of our intellect require to be trained for the more difficult speculations by practice in the easier. For the same reasons, the study of the inorganic world should take precedence of the organic. For, in the first place, the laws of the more universal mode of existence have a preponderating influence over those of the more special modes; and in the second place it is clearly incumbent on us to begin the study of the Positive method with its simplest and most characteristic applications. I need not dwell further upon principles so fully established in my former work.