As empiricism sprang from the striving to subject the intellectual to the material, to materialize the spiritual, so on the other hand, idealism had its source in the effort to spiritualize the material, or so to apprehend the conception of mind that matter could be subsumed under it. To the empiric-sensualistic direction, mind was nothing but refined matter, while to the idealistic direction matter was only degenerated (_vergröbert_) mind (“a confused notion,” as Leibnitz expresses it). The former, in its logical development, was driven to the principle that only material things exist, the latter (as with Leibnitz and Berkeley) comes to the opposite principle, that there are only souls and their ideas. For the partial realistic standpoint, material things were the truly substantial. But for the idealistic standpoint, the substantial belongs alone to the intellectual world, to the Egos. Mind, to the partial realism, was essentially void, a _tabula rasa_, its whole content came to it from the external world. But a partial idealism sought to carry out the principle that nothing can come into the mind which had not at least been preformed within it, that all its knowledge is furnished it by itself. According to the former view knowledge was a passive relation, according to the latter was it wholly active. While, in fine, a partial realism had attempted to explain the becoming in nature for the most part through real, _i. e._ through mechanical motives (_l’homme machine_ is the title of one of la Mettrie’s writings), idealism had sought an explanation of the same through ideal motives, _i. e._ teleologically. While the former had made its prominent inquiry for moving causes, and had, indeed, often ridiculed the search for a final cause; it is final causes toward which the latter directs its chief aim. The mediation between mind and matter, between thought and being, will now be sought in the final cause, in the teleological harmony of all things (_pre-established harmony_). The standpoint of Leibnitz may thus be characterized in a word.