The strictly philosophic term phenomenon, to which science has taken so kindly, is in itself an explicit avowal of something beyond the phenomenal. Spencer is careful to insist upon this relation of the phenomenal to the noumenal. His _Synthetic Philosophy_ opens with an exposition of this non-relative or absolute, without which the relative itself becomes contradictory. It is an essential part of Spencer's doctrine to maintain that our consciousness of the absolute, indefinite as it is, is positive and not negative. 'Though the absolute cannot in any manner or degree be known, in the strict sense of knowing, yet we find that its positive existence is a necessary datum of consciousness. The belief which this datum of consciousness constitutes has a higher warrant than any other belief whatsoever.' In short, the absolute or noumenal, according to Spencer, though not known as the phenomenal or relative is known, is so far from being for knowledge a pure blank, that the phenomenal, which is said to be known, is in the strict sense inconceivable without it. This actuality behind appearances, without which appearances are unthinkable, is by Spencer identified with that ultimate verity upon which religion ever insists. Religion itself is a phenomenon, and the source and secret of most complex and interesting phenomena. It has always been of the greatest importance in the history of mankind. It has been able to hold its own in face of the attacks of science. It must contain an element of truth. All religions, however, assert that their God is for us not altogether cognisable, that God is a great mystery. The higher their rank, the more do they acknowledge this. It is by the flippant invasion of this mystery that the popular religiosity offends. It talks of God as if he were a man in the next street. It does not distinguish between merely imaginative fetches into the truth, and presumably accurate definition of that truth. Equally, the attempts which are logically possible at metaphysical solutions of the problem, namely, theism, pantheism, and atheism, if they are consistently carried out, assert, each of them, more than we know and are involved in contradiction with themselves. But the results of modern physics and chemistry reveal, as the constant element in all phenomena, force. This manifests itself in various forms which are interchangeable, while amid all these changes the force remains the same. This latter must be regarded as the reality, and basis of all that is relative and phenomenal. The entire universe is to be explained from the movements of this absolute force. The phenomena of nature and of mental life come under the same general laws of matter, motion, and force.