In the introductory chapter of this work I have said that all religions are in effect ‘working hypotheses,’ by which men seek to reconcile the highest aspirations of their nature with the facts of the universe, and bring the whole into some harmonious concordance. I said so for the following reasons. In a discussion at the Metaphysical Society on the uniformity of laws of nature, recorded in the ‘Nineteenth Century,’ Huxley is represented as saying that he considered this uniformity, not as an axiomatic truth like the first postulates of geometry, but as a ‘working hypothesis’; adding, however, that it was an hypothesis which had never been known to fail. To this some distinguished advocates of Catholic theology replied, that their conviction was of a higher nature, for their belief in God was a final truth which was the basis of their whole intellectual and moral nature, and which it was irrational to question. This is in effect Cardinal Newman’s celebrated argument of an ‘illative sense,’ based on a complete assent of all the faculties, and which was therefore a higher authority than any conclusions of science. The answer is obvious, that complete assent, so far from being a test of truth, is, on the contrary, almost always a proof that truth has not been attained, owing either to erroneous assumptions as to the premises, or to the omission of important factors in the solution of the problem. To give an instance, I suppose there could not be a stronger case of complete assent than that of the Inquisitors who condemned the theories of Galileo. They had in support of the proposition that the sun revolved round the earth the testimony of the senses, the universal belief of mankind in all ages, the direct statement of inspired Scripture, the authority of the infallible Church. Was all this to be set aside because some ‘sophist vainly mad with dubious lore’ told them, on grounds of some new-fangled so-called science, that the earth revolved round its axis and round the sun? ‘No; let us stamp out a heresy so contrary to our “illative sense,” and so fatal to all the most certain and cherished beliefs of the Christian world, to the inspiration of the Word of God, and to the authority of His Church.’ ‘E pur si muove,’ and yet the earth really did move; and the verdict of _fact_ was that Galileo and science were right, and the Church and the illative sense wrong.