of which is traceable throughout every department of nature.

Mr. Herbert Spencer's definition of it is equally clear and concise: "Evolution is a change from an indefinite, incoherent homogeneity, to a definite, coherent heterogeneity; through continuous differentiations and integrations." 1

Its absolute universality of operation he thus expresses: "Whether it be in the development of the Earth, in the development of Life upon its surface, in the development of Society, of Government, of Manufactures, of Commerce, of Language, of Literature, Science, Art, this same advance from the simple to the complex, through successive differentiations, holds uniformly. From the earliest traceable cosmical changes down to the latest results of civilization, we shall find that the transformation of the homogeneous into the heterogeneous, is that in which Evolution essentially consists.” 2

In this last sentence we have not merely the "transformation" "in which evolution essentially consists;" we have also the assump

1 "First Principles." Williams & Norgate, 1862, p. A subsequent definition is given below. See Appendix, Note B.

216.

2 Ibid., pp. 148, 149.

tion that "the latest results of civilization' have been evolved, in the way of necessary and inevitable consequence, from "the earliest traceable cosmical changes." Human life, with all its inexhaustible possibilities, has been evolved from life infra-human. The life of the lower animals, like that of plants, was in the first instance evolved from non-living matter; as that matter itself was evolved from "cosmic vapour."

Professor Tyndall, as we have seen, tells us that "the world-even the clerical world-has for the most part settled down in the belief that Mr. Darwin's book simply reflects the truth of Nature that we who are now 'foremost in the files of time' have come to the front through almost endless stages of promotion from lower to higher forms of life." 1 And again :

"It is now generally admitted that the man of to-day is the child and product of incalculable antecedent time. His physical and intellectual textures have been woven for him during his passage through phases of history and forms of existence which lead the mind back to an abysmal past."2 "If to any one of us were given the privilege of looking back through the

1 "Science and Man." Fortnightly Review, vol. xxii. p. 611.

æons across which life has crept towards its present outcome, his vision would ultimately reach a point when the progenitors of this assembly could not be called human."1 "No one indeed doubts now that all the higher types of life with which the earth teems have been developed by the patient process of evolution from lower organisms, and in logical consistency we are bound to trace back the series to the simplest forms of protoplasm, which the microscope reveals to us as living units. But all this is but the outcome of life from life, and leaves us without an approach to a solution of the mighty question of the origin of life. There was a time when the earth was a red-hot melted globe, on which no life could exist. In course of ages its surface cooled; but, to quote the words of one of our greatest savans, 'when it first became fit for life there was no living thing upon it.' How then are we to conceive the origination of organized creatures?" 2

Professor Huxley, propounding to the British Association3 the tenets of what he called his

1 "Science and Man." Fortnightly Review, vol. xxii. p. 611.

2 "The Germ Theory and Spontaneous Generation.” Contemporary Review, vol. xxix. pp. 901, 902.

3 In the Presidential Address for 1870.

"philosophic faith" on this subject, has answered this question with his characteristic clearness of enunciation:

"If it were given me to look beyond the abyss of geologically recorded time to the still more remote period when the earth was passing through physical and chemical conditions, which it can no more see again than a man can recall his infancy, I should expect to be a witness of the evolution of living protoplasm from not living matter." 1

To the same effect, and not less articulately, Professor Tyndall :

"The problem before us is, at all events, capable of definite statement. We have on the one hand strong grounds for concluding that the earth was once a molten mass. We now find it not only swathed by an atmosphere and covered by a sea, but also crowded with living things. The question is, how were they introduced? The conclusion of science, which recognises unbroken causal connection between the past and the present, would undoubtedly be that the molten earth contained within it the elements of life, which grouped themselves into their present forms as the planet cooled. The difficulty and reluctance encoun

1 66 Critiques and Addresses." Macmillan, 1873, p. 239.

tered by this conception, arise solely from the fact that the theologic conception obtained a prior footing in the human mind. Did the latter depend upon reasoning alone, it could not hold its ground for an hour against its rival. Were not man's origin implicated, we should accept without a murmur the derivation of animal and vegetable life from what we call inorganic nature. The conclusion of pure intellect points this way and no other." 1

In other words-and to sum up all that has been said in one short but authoritative sentence-"The doctrine of Evolution derives man in his totality from the interaction of organism and environment through countless ages past." 2

And this it does, whatever may become of Darwinism. On this head, as well as on the illimitable sphere of its operation, we have the final conclusion of Professor Huxley :

"But even leaving Mr. Darwin's views aside, the whole analogy of natural operations furnishes so complete and crushing an argument against the intervention of any but what are termed

1 "Materialism and its Opponents." Fortnightly Review, vol. xviii. pp. 596, 597.

2 Prof. Tyndall's "Belfast Address," p. 59.