parent,—at first in a very slight degree, but ultimately, as generations advance, to an extent which renders the latest progeny of the species widely dissimilar from the earlier. We are then directed to observe that the earth is undergoing from time to time changes in its atmospheric conditions; in other words, that the forms of life which exist on the globe are periodically encircled by new environments. We are called to consider that when these changes of climate occur, they will find the existing forms of life unequally prepared for them. This, of course, follows from the fact that the existing forms of life have become themselves unequal. If like does not beget an exact likeness, if the latest progeny of the species exhibits a marked divergence from its earlier individual members, it follows that there are already differences in the species which must render one member much more adapted than another for the climatic change. Hence it is that the doctrine of evolution has called in at this point the aid of a fourth and more powerful influence, to which it has given the name of natural selection, or the survival of the fittest. By that name it designs to emphasise the truth that those members of the species which outlive the change of climate are precisely those that have already been most prepared for the change by their process of divergence from the original type. The earlier forms having been adapted to an earlier environment, are unable

to bear the strain of the new conditions, and accordingly succumb and die; the latest forms having had time by the very process of heredity to modify their original type, are able in the first instance to adapt themselves, and ultimately to assimilate themselves, to those changes which have destroyed their predecessors, and so to become the progenitors of another and an essentially different

race.

Such is in brief outline the doctrine which has been promulgated by Mr Darwin and elaborated by Mr Herbert Spencer. It professes to show the process by which the original unity of life has been broken up into such varieties as present the appearance of specially created species. It exhibits to us that line of evolution on which, by travelling backward, we shall be able to find again the original unity out of which the varieties have come. It tells us that by following this line we shall be liberated from the primitive and puerile errors of religious speculation. We shall no longer seek to interpret nature by calling in the aid of something which is supernatural or unnatural; we shall come to interpret her by her own light. We shall find the explanation of the manifestations and the changes around us not in the intervention of some celestial power which from time to time breaks through the original arrangements of the universe, but in the presence and action of those

laws of movement and of life which themselves constitute the original arrangement of nature, and which are themselves amply adequate to account for all natural operations.

Such is the goal which the doctrine of evolution proposes to itself-a goal which, if achieved, would certainly lead to the elimination from human thought of the very idea of the supernatural. But now we have to point out a remarkable circumstance, and it is this, that the doctrine of evolution has deserted its own goal, has abandoned in fact the aim which it proposed in words. If we take as its representative the philosophy of Mr Herbert Spencer, we shall be more and more impressed with the conviction that the line of demarcation between evolutionism and creationism has been obliterated by the doctrine of evolution itself. Mr Spencer, like Mr Darwin, starts by opposing the idea of evolution to the idea of special creation, and professes to trace back the varied phenomena of the universe to the operation of a common element. But when Mr Spencer has completed his task, he finds that so far from having reached the solution of a mystery, he has in reality only discovered the spot where the mystery lies. He traces back the varieties of life and nature to some primitive. material germ, and then he tells us that this material germ is only a symbol. When he has

reached his last analysis he finds that the entire process has been only an analysis of symbols. These so-called forms of matter are but the shadows of something which is not material — something which manifests itself in movement, and which, therefore, for want of a better name, we must call force. Behind the manifestations of things, behind the changes which the eye can see and the ear can hear, behind the tremor of nerves and the weaving of tissues, there exists and operates perpetually a Power which is quite inscrutable. It underlies all things, it constitutes the being of all things, yet it is itself indiscernible. Mr Spencer calls it the Unknowable, but it would be a mistake to think that by that term he designs to designate a mere negation. The Unknowable is with him exactly identical with that which the metaphysician calls the transcendental, or which the German idealist calls the Absolute. The very confession that it is unknown is really a confession that the doctrine of evolution, to be adequate, must be supplemented by the doctrine of a specially creative Power. Why does Mr Spencer not stop short with his germ-cell of plant-life, or with his fire-cloud of cosmical life? Why does he not arrest himself when he has elucidated in the animal world the operation of the laws called heredity and natural selection, or when he has traced back in the phys

ical world the "definite coherent heterogeneity," to the "indefinite incoherent homogeneity"? It is because Mr Spencer is acute enough to feel and candid enough to admit that none of these things. are principles of unity at all. He sees that the most fundamental phenomena of nature are effects and not causes, that the explanation of things. needs itself to be explained. Nay, he sees something more than that. To him all the phenomena of nature are equally effects; one thing is not more mysterious than another-there is no distinction between great and small. The movement of a muscle is in itself not less incomprehensible than the united movement of the solar system; the minutest and most commonplace act in the visible creation is as incapable of explaining its own existence, as is the grandest process of the universe conducted on the largest scale.

Under these circumstances and guided by these convictions, what does Mr Spencer do? He calls in the aid of something transcendental—something whose existence and nature he confesses to be inexplicable, but which he holds to be required in order to explain other things. This mysterious, inscrutable, incomprehensible agency Mr Spencer calls Force. He does not mean to designate the force of gravity, or the force of repulsion, or the force of cohesion; these are themselves only forms,

1 See his 'Principles of Biology,' vol. i. p. 491.