The object of this work is to examine in a popular manner, and to test by scientific facts and principles the validity of that multiform and brilliant philosophy of the universe which has taken so deep hold of the science and literature of our time. The task is a somewhat ungracious one, especially in England whose people are naturally proud of discoveries and generalisations which, originating among themselves, have taken the world by storm. It is also extremely difficult, because of the dazzling and attractive nature of the hypothesis of evolution, the dashing and plausible character of the arguments by which it is sustained, and its all-embracing scope, which enables it to account for everything that has previously been mysterious. Besides this, it is of the nature of this protean philosophy that it should itself be in process of evolution from day to day, and thus to be in so rapid motion that it changes its features momentarily while one endeavours to sketch it.

Why then attempt such a task? The answer is two-fold—general and personal. First, the world of general readers is captivated, dazzled and perplexed by the new philosophy, and greatly needs some clear and intelligible exposition of its nature and tendency, some classification of its variations, and some attempt to explain its agreement or discordance with science iad religion. Secondly, the writer of the following pages has of late years been besieged by so many letters and inquiries respecting this subject, to which he has incidentally referred in popular books on science, that it becomes necessary in self-defence and to save time to prepare an answer which may meet all demands of this kind.