A great reformer of the last generation, finding that the idea of Nature was constantly put forward to thwart his most cherished schemes, prepared a mine for its destruction which was only exploded after his death. Seldom has so powerful a charge of logical dynamite been collected within so small a space as in Mill’s famous Essay on Nature. But the immediate effect was less than might have been anticipated, because the attack was supposed to be directed against religion, whereas it was only aimed at an abstract metaphysical dogma, not necessarily connected with any theological beliefs, and held by many who have discarded all such beliefs. A stronger impression was, perhaps, produced by the nearly simultaneous declaration of Sir W. Gull—in reference to the supposed _vis medicatrix naturae_—that, in cases of disease, ‘what Nature wants is to put the man in his coffin.’ The new school of political economists have also done much to show that legislative interference with the ‘natural laws’ of wealth need by no means be so generally mischievous as was once supposed. And the doctrine of Evolution, besides breaking down the old distinctions between Nature and Man, has represented the former as essentially variable, and therefore, to that extent, incapable of affording a fixed standard for moral action. It is, however, from this school that a new attempt to rehabilitate the old physical ethics has lately proceeded. The object of Mr. Herbert Spencer’s _Data of Ethics_ is, among other points, to prove that a true morality represents the ultimate stage of evolution, and reproduces in social life that permanent equilibration towards which every form of evolution constantly tends. And Mr. Spencer also shows how evolution is bringing about a state of things in which the self-regarding shall be finally harmonised with the social impulses. Now, it will be readily admitted that morality is a product of evolution in this sense that it is a gradual formation, that it is the product of many converging conditions, and that it progresses according to a certain method. But that the same method is observed through all orders of evolution seems less evident. For instance, in the formation, first of the solar system, and then of the earth’s crust, there is a continual loss of force, while in the development of organic life there is as continual a gain; and on arriving at subjective phenomena, we are met by facts which, in the present state of our knowledge, cannot advantageously be expressed in terms of force and matter at all. Even if we do not agree with George Sand in thinking that self-sacrifice is the only virtue, we must admit that the possibility, at least, of its being sometimes demanded is inseparable from the idea of duty. But self-sacrifice cannot be conceived without consciousness; which is equivalent to saying that it involves other than mechanical notions. Thus we are confronted by the standing