We have said that the disbelievers in such doctrines form a minority of the race; but at the same time it must be acknowledged that the strength of this minority has of late years greatly increased, so much so that at the present moment it numbers in its ranks not a few of the most intelligent, the most earnest, and the most virtuous of men. It is, however, possible that, could we examine these, we should find them to be unwilling disbelievers, compelled by the working of their intellects to abandon the desire of their hearts, only after many struggles, and with much bitterness of spirit. Others, again, without absolutely abandoning all hope of a future existence, are yet full of doubt regarding it, and have settled down into the belief that we cannot come to any reasonable conclusion upon the subject. Now, these men can have had nothing to gain, but rather much to lose, in arriving at this result. It has been reached by them with reluctance, with misgivings, not without a certain kind of persecution, nor without the loss of friends and the stirring up of strife; still they have fearlessly looked things in the face, and have followed whithersoever they imagined they were led by facts, even to the brink of an abyss. It is the object of the present volume to examine the intellectual process which has brought about such results, and we hope to be able to show not only that the conclusion at which these men have arrived is not justified by what we know of the physical universe, but that on the other hand there are many lines of thought which point very strongly towards an opposite conclusion. 2. A division as old as Aristotle separates[3] speculators into two great classes,—those who study the How of the Universe, and those who study the Why. All men of science are embraced in the former of these, all men of religion in the latter. The former regard the Universe as a huge machine, and their object is to study the laws which regulate its working; the latter again speculate about the object of the machine, and what sort of work it is intended to produce. The disciples of How are accused by their adversaries of being willing to sacrifice the individual to the system; while the disciples of Why are accused by _their_ adversaries of being willing to sacrifice the system to the individual.