In the first place they may acknowledge the truth of our position and change their views; or, secondly, they may combat our argument regarding the alleged incompatibility of their position with the Principle of Continuity; or, lastly, they may decline to accept this scientific principle in matters which concern their faith. What we complain of is, that the members of this school have chosen none of these alternatives, but have rather attempted to brand us as infidels and materialists, apparently forgetting (as usual) that such a method of conducting a discussion is neither Christ-like nor convincing. But while one class of religious men have tried to brand us with these names, those of another school consider our theology narrow and gloomy. We reply to these men that we do not pretend to be theologians in any sense of the word. Our position in this respect has been greatly misunderstood. We are, no doubt, endeavouring to bring about a reconciliation between science and religion. In order to accomplish this we must first find out what is the fundamental principle of science, next what is the fundamental creed of the great majority of Christians, and then endeavour to show that the two are not incompatible with each other. In carrying out this process we have been led to regard the Principle of Continuity as the great law which regulates scientific inquiry, and there cannot be a doubt that the Old and New Testaments are regarded as authoritative expositions of religious truth by the great majority of the Church of Christ. Now we find that the expressions in the Scriptures regarding the future of man and the constitution of the unseen world, taken in their obvious, if not absolutely literal meaning, are not inconsistent with scientific deductions from the Principle of Continuity. We know very well that, especially of late years, a multitude of religious schools have risen up who take many of these expressions in a non-literal and far from obvious acceptation, and who, perhaps, do not accord the same authority to the writers as was formerly done. Into the disputes between these various religious schools we do not pretend to enter, nor do we see that the Shibboleths of such schools can be affected by our arguments, inasmuch as their discussions have, in the great majority of cases, nothing whatever to do with Physical principles. They are rather founded on historical, or moral, or metaphysical considerations, all of which are foreign to our argument. Having no pretensions to a title which we certainly do not covet, we trust that we shall no longer be regarded as theologians either of a narrow and gloomy, or a lax and heretical school, or indeed of any school whatsoever. _September 1875._ PREFACE TO THE FOURTH AND FIFTH EDITIONS.