To complete even in outline the vast sweep of his projected Synthetic Philosophy two steps more remained for Spencer to take. The law of evolution had to be brought under the recently-discovered law of the Conservation of Energy, or, as he called it, the Persistence of Force, and the whole of unified science had to be reconciled with religion. The first problem was solved by interpreting evolution as a redistribution of matter and motion--a process in which, of course, energy is neither lost nor gained. The second problem was solved by reducing faith and knowledge to the common denominator of Agnosticism--a method that found more favour with Positivists (in the wide sense) than with Christian believers. Herbert Spencer was disappointed to find that people took more interest in the portico (as he called it in a letter to the present writer)--that is to say, the metaphysical introduction to his philosophical edifice--than in its interior. He probably had some suspicion that the portico was mere lath and plaster, while he felt sure that the columns and architraves behind it were of granite. The public, however, besides their perennial interest in religion, might be excused for giving more attention to even a baroque exterior with some novelty about it than to the formalised eclecticism of what stood behind it. Unfortunately, they soon found that the alleged reconciliation was a palpable sham. Religion is nothing if not a revelation, and an unknowable God is no God at all. Even the pretended proofs of that poor residual deity involved their author in the transparent self-contradiction of calling the universe the manifestation of an Unknowable Power. Then the relations between this Power (such as it was) and the Energy (or Force) whose conservation (or persistence) was the very first {142} of First Principles seemed hard to adjust. Either energy is created, or it is not. In the one case, what becomes of its eternity? in the other case, what need is there to assume a Power (knowable or not) behind it? Science will not shrink back before such a phantom, nor will Religion adore it.