of those habits of abstraction which are necessary to the philosopher. The same theory then which explains the mental evolution of Humanity, lays down the true method by which our abstract conceptions should be classified; thus reconciling the conditions of Order and Movement, hitherto more or less at variance. Its historical clearness and its philosophical force strengthen each other, for we cannot understand the connexion of our conceptions except by studying the succession of the phases through which they pass. And on the other hand, but for the existence of such a connexion, it would be impossible to explain the historical phases. So we see that for all sound thinkers, History and Philosophy are inseparable. [Therefore we are in a position to proceed at once with the work of social regeneration] A theory which embraces the statical as well as the dynamical aspects of the subject, and which fulfils the conditions here spoken of, may certainly be regarded as establishing the true objective basis on which unity can be established in our intellectual functions. And this unity will be developed and consolidated as our knowledge of its basis becomes more satisfactory. But the social application of the system will have far more influence on the result than any overstrained attempts at exact scientific accuracy. The object of our philosophy is to direct the spiritual reorganization of the civilized world. It is with a view to this object that all attempts at fresh discovery or at improved arrangement should be conducted. Moral and political requirements will lead us to investigate new relations; but the search should not be carried farther than is necessary for their application. Sufficient for our purpose, if this incipient classification of our mental products be so far worked out that the synthesis of Affection and of Action may be at once attempted; that is, that we may begin at once to construct that system of morality under which the final regeneration of Humanity will proceed. Those who have read my _Positive Philosophy_ will, I think, be convinced that the time for this attempt has arrived. How urgently it is needed will appear in every part of the present work. [Error of identifying Positivism with Atheism, Materialism, Fatalism, or Optimism. Atheism, like Theology, discusses insoluble mysteries] I have now described the general spirit of Positivism. But there are two or three points on which some further explanation is necessary, as they are the source of misapprehensions too common and too serious to be disregarded. Of course I only concern myself with such objections as are made in good faith.