One other matter remains to be considered with reference to this world-eject as sanctioned by Monism. It leaves us free to regard all natural causation as a direct exhibition of psychism. The prejudice against anything approaching a theistic interpretation of the Universe nowadays arises chiefly from the advance of physical science having practically revealed the ubiquity of natural causes. It is felt that when a complete explanation of any given phenomenon has been furnished in terms of these causes, there is no need to go further; the phenomenon has been rendered intelligible on its mechanical side, and therefore it is felt that we have no reason to suppose that it presents a mental side--any supplementary causation of a mental kind being regarded as superfluous. Even writers who expressly repudiate this reasoning prove themselves to be habitually under its influence; for we constantly find that such writers, after conceding the mechanical explanations as far as these have been _proved_, take their stand upon the more intricate phenomena of Nature where, as yet, the mechanical explanations are not forthcoming. Whether it be at the origin of life, the origin of sentiency, of instinct, of rationality, of morality, or of religion, these writers habitually argue that here, at least, the purely mechanical interpretations fail; and that here, consequently, there is still room left for a psychical interpretation. Of course the pleading for theism thus supplied is seen by others to be of an extremely feeble quality; for while, on the one hand, it rests only upon ignorance of natural causation (as distinguished from any knowledge of super-natural causation), on the other hand, abundant historical analogies are available to show that it is only a question of time when pleading of this kind will become more and more restricted in its subject-matter, till eventually it be altogether silenced. But the pleading which Monism is here able to supply can never be silenced.