We must therefore ask the positivist for his warrant, on the one hand, in denying the existence of a world of substance, underneath the fleeting phenomena of being, _out of which a revelation may emerge_, apprehensible by man; and on the other, in denying to man positive knowledge of the infinite as a substance. We must remind him that infinite and finite, absolute and relative, substance and phenomena, are terms of a relation: while we ask him for his warrant in differentiating these terms, and proclaiming that the one set are knowable and known, the others unknown and unknowable. He arbitrarily singles out one of the two factors which together constitute a relation, and are only known as complementary terms, and he bestows upon it a spurious honour, by proclaiming that it alone is intelligible, while he relegates the other term to the region of darkness. We ask him on what ground he does so? and whether the law of contrast does not render phenomena as unintelligible, without substance, as substance without phenomena? Can we pronounce the one to be known and the other unknown, merely because the former reaches us through the five gateways of sense, and the latter through the avenue of intuition? Now, no wise theist ever asserted that God was phenomenally known. God is no phenomenon, but the noumenal essence underlying all phenomena. We have admitted and contended that no study of the laws of the universe can give us direct information as to the first cause; for a first cause could never be revealed to the senses, nor be an inference deduced from the data which sense supplies. The assertion therefore, that nature (of which the physical sciences are the interpretation) does not reveal God by its phenomena, is as strongly asserted by the theist as by the positivist. It may reveal his footprints, but we only know whose foot has left its mark on nature when we have learned _from another source_ that He _is_. As little, however, can the laws of nature discredit faith in a first cause, which springs from a region at once beneath, above, and beyond phenomena. And our theistic faith is not an _inference_; it is a _postulate_: an axiomatic truth, affirmed on the report of that intuition, of which the root is planted so firmly in the soil of consciousness, that no form of the positivist philosophy can tear it thence. Let science, therefore, march as it will, and where it will, being hemmed in by the very laws of the universe which give rise to it, and of which it is the exposition, it cannot interfere with or encroach upon the theistic intuition. If there be a region behind phenomena and their laws, accessible to knowledge or to philosophic faith, no conclusion gathered from the scientific survey can touch it, whether to discredit or attest.