To reduce matters to order, we may confidently assert that the only reasonable and defensible alternative to our hypothesis (or, at least, something similar to it) is, the stupendous pair of assumptions that visible matter is _eternal_, and that IT IS ALIVE. (See § 240.) If any one can be found to uphold notions like these (from a scientific point of view), we shall be most happy to enter the lists with him. We have made numerous small though sometimes important changes in the text, but none of them at all modify the general tenor of the work as it first appeared two months ago. PREFACE TO THE THIRD EDITION. We have reason to think that notwithstanding all we have said, the position we take is not yet clearly understood, and we would therefore utilise the Preface to our Third Edition to put ourselves right with the public on this vital point. To begin with the scientific side of our argument, we must once more make the statement that it is not we who are the dogmatists, but rather that school of scientific men who assert the incompatibility of science with Christianity. Persistent as they have been in their endeavours to close the door leading from the seen to the unseen, we as resolutely maintain that it must be left open. This class take credit to themselves for having thus barred the entrance to a throng of superstitious fancies which would inevitably rush through an open avenue—forgetting that they have by the same act barred the way to all the higher aspirations of man. But though we have founded no argument for immortality on the existence of these higher aspirations, we cannot allow our adversaries to bar the way upon the plea that it would inevitably be the resort of unworthy passengers. If it be the King’s highway it must be left open; if the unseen universe be a reality, surely we are not to dismiss it from our minds lest some people might entertain absurd views regarding its relation to the present visible universe. Such fancies are no new thing in the progress of knowledge. When two things are known to exist, we may have ten thousand erroneous hypotheses regarding their mutual relations, but only one true theory. In the next place, we would say one word to that religious school which is more particularly affected by our present inquiry,—we mean the school who assert the resurrection of our material bodies, and a grossly material future state. We have endeavoured to explain to this class of men that their belief is inconsistent with the integrity of that Principle of Continuity which underlies not only all scientific inquiry, but all action of any kind in this world of ours. Under these circumstances such men have three honest alternatives before them.