This philosophical estimate of Materialism explains how it is that it has been brought as a charge against Positivism, and at the same time proves the deep injustice of the charge. Positivism, far from countenancing so dangerous an error, is, as we have seen, the only philosophy which can completely remove it. The error arises from certain tendencies which are in themselves legitimate, but which have been carried too far; and Positivism satisfies these tendencies in their due measure. Hitherto the evil has remained unchecked, except by the theologico-metaphysical spirit, which, by giving rise to what is called Spiritualism, has rendered a very valuable service. But useful as it has been, it could not arrest the active growth of Materialism, which has assumed in the eyes of modern thinkers something of a progressive character, from having been so long connected with the cause of resistance to a retrograde system. Notwithstanding all the protests of the spiritualists, the lower sciences have encroached upon the higher to an extent that seriously impairs their independence and their value. But Positivism meets the difficulty far more effectually. It satisfies and reconciles all that is really tenable in the rival claims of both Materialism and Spiritualism; and, having done this, it discards them both. It holds the one to be as dangerous to Order as the other to Progress. This result is an immediate consequence of the establishment of the encyclopædic scale, in which each science retains its own proper sphere of induction, while deductively it remains subordinate to the science which precedes it. But what really decides the matter is the fact that such paramount importance, both logically and scientifically, is given by Positive Philosophy to social questions. For these are the questions in which the influence of Materialism is most mischievous, and also in which it is most easily introduced. A system therefore which gives them the precedence over all other questions must hold Materialism to be quite as obstructive as Spiritualism, since both are alike an obstacle to the progress of that science for the sake of which all other sciences are studied. Further advance in the work of social regeneration implies the elimination of both of them, because it cannot proceed without exact knowledge of the laws of moral and social phenomena. In the next chapter I shall have to speak of the mischievous effects of Materialism upon the Art or practice of social life. It leads to a misconception of the most fundamental principle of that Art, namely, the systematic separation of spiritual and temporal power. To maintain that separation, to carry out on a more satisfactory basis the admirable attempt made in the Middle Ages by the Catholic Church, is the most important of political questions. Thus the antagonism of Positivism to Materialism rests upon political no less than upon philosophical grounds.