But all Positive speculations owe their first origin to the occupations of practical life; and, consequently, they have always given some indication of their capacity for regulating our active powers, which had been omitted from every former synthesis. Their value in this respect has been and still is materially impaired by their want of breadth, and their isolated and incoherent character; but it has always been instinctively felt. The importance that we attach to theories which teach the laws of phenomena, and give us the power of prevision, is chiefly due to the fact that they alone can regulate our otherwise blind action upon the external world. Hence it is that while the Positive spirit has been growing more and more theoretical, and has gradually extended to every department of speculation, it has never lost the practical tendencies which it derived from its source; and this even in the case of researches useless in themselves, and only to be justified as logical exercises. From its first origin in mathematics and astronomy, it has always shown its tendency to systematize the whole of our conceptions in every new subject which has been brought within the scope of its fundamental principle. It exercised for a long time a modifying influence upon theological and metaphysical principles, which has gone on increasing; and since the time of Descartes and Bacon it has become evident that it is destined to supersede them altogether. Positivism has gradually taken possession of the preliminary sciences of Physics and Biology, and in these the old system no longer prevails. All that remained was to complete the range of its influence by including the study of social phenomena. For this study metaphysics had proved incompetent; by theological thinkers it had only been pursued indirectly and empirically as a condition of government. I believe that my work on Positive Philosophy has so far supplied what was wanting. I think it must now be clear to all that the Positive spirit can embrace the entire range of thought without lessening, or rather with the effect of strengthening its original tendency to regulate practical life. And it is a further guarantee for the stability of the new intellectual synthesis that Social science, which is the final result of our researches, gives them that systematic character in which they had hitherto been wanting, by supplying the only connecting link of which they all admit.