II. We turn now to the Second Form of doubt raised by the doctrine of Evolution: under which it weakens our objective trust in an originating Mind.
A naturalist who to his own satisfaction has traced the pedigree of the human intellect, conscience, and religion, to Ascidian skin-bags sticking to the sea-side rocks, is not likely to arrest the genealogy there, at a stage so little fitted to serve as a starting-point of derivative being. Or, if his own retreat should go no further, others will take up the regressive race, and, soon passing the near and easy line into the vegetable kingdom, will work through its provinces to its lichen-spotted edge: and, after perhaps one shrinking look, will dare the leap into the dead realm beyond, and bring home the parentage of all to the primitive elements of "matter and force." To give effect to this extension over the universe at large of the theory of Evolution, the scientific imagination of our day has long been meditating its projected book of Genesis, and has already thrown out its special chapters here and there; and though the scenes of the drama as a whole are not yet arranged, the general plan is clear: that the Lucretian method is the true one; that nothing arises for a purpose, but only from a power; that no Divine Actor therefore is required, but only atoms extended, resisting, shaped, with spheres of mutual attraction and repulsion; that, with these minima to begin with, a growth will follow of itself by which the maxima will be reached; and that thus far the chief and latest thing it has done is the apparition of Mind in the human race and civilization in human society, conferring upon man the melancholy privilege of being, so far as he knows, at the summit of the universe.
The main support of this doctrine is found in two arguments, supplied respectively by physical science and by natural history; each of which we will pass under review.
i. The former relies on the new scientific conception of the Unity of Force. When Newton established the composition of Light in his treatise on Optics, and the law of Gravitation in his Principia, he conceived himself to be treating of two separate powers of nature, between which, quick as he was to seize unexpected relations, he dreamt of no interchange. Yet now it is understood that when collisions occur of bodies gravitating on opposite lines, the momenta that seem to be killed simply burst into light and heat. When Priestley's experiments detected the most important chemical element on the one hand, and the fundamental electrical laws on the other, he seemed to move on paths of research that had no contact. Yet, in the next generation, chemical compounds were resolved by electricity; which again turns up in exchange for magnetism, and can pass into motion, heat, and light. To see the transmigration of natural agency, trace only through a few of its links the effect of the sunshine on the tropic seas. So far as it warms the mass of waters, either directly or through the scorched shores that they wash, it stirs them into shifting layers and currents, and creates mechanical power. But it also removes the superficial film; and thus far spends itself, not in raising the temperature, but in changing the form from liquid to vapor, and so altering the specific gravity as to transfer what was on the deep to the level of the mountain-tops. It is the Pacific that climbs and crowns the Andes, resuming on the way the liquid state in the shape of clouds, and as it settles crystallizing into solid snow and ice. The original set of solar rays have now played their part, and made their escape elsewhere. But there is sunshine among the glaciers too, which soon begins to resolve the knot that has been tied, and restore what has been stolen. It sets free the waters that have been locked up, and lets their gravitation have its play upon their flow. As they dash through ravines, or linger in the plains, they steal into the roots of grass and tree, and by the tribute which they leave pass into the new shape of vital force. And if they pass the homesteads of industry, and raise the food of a civilized people, who can deny that they contribute not only to the organic, but to the mental life, and so have run the whole circuit from the lowest to the highest phase of power? That the return back may be traced from the highest to the lowest, is shown by every effort of thought and will; which through the medium of nervous energy in one direction sets in action the levers of the limbs, and in another works the laboratory of the organic life, and forms new chemical compounds, of which some are reserved for use, while others pass into the air as waste. Still further: all doubt of identity in the force which masks itself in these various shapes is said to be removed by the test of direct measurement before and after the change. The heating of a pound of water by one degree has its exact mechanical equivalent;[13] and a given store of elevated temperature will overcome the same weights, whether applied directly to lift them, or turned first into a thermo-electric current, so as to perform its task by deputy.[14] The inference drawn from the phenomena of which these are samples is no less than this: that each kind of force is convertible into any other, and undergoes neither gain nor loss upon the way; so that the sum-total remains for ever the same, and is only differently represented as the proportions change amongst the different forms of life, and between the organic and the inorganic realms. Hence arises the argument that, in having any force, you have virtually all; and that, assuming only material atoms as depositories of mechanical resistance and momentum, you can supply a universe with an exhaustive cosmogony, and dispense with the presence of Mind, except as one of its phenomena.
[13] Viz., the fall of 772 lbs. through a foot. See Mr. Joule's Experiments in Grove's Correlation of Physical Forces, p. 34, 5th ed.
[14] See Grove's Correlation, p. 255, 5th ed.
To test this argument, let us grant the data which are demanded, and imagine the primordial space charged with matter, in molecules or in masses, in motion or rest, as you may prefer. Put it under the law of gravitation, and invest it with what varieties you please of density and form. Thus constituted, it perfectly fulfils all the conditions you have asked; it presses, it moves, it propagates and distributes impulse, is liable to acceleration and retardation, and exhibits all the phenomena with which any treatise on Mechanics can properly deal. In order, however, to keep the problem clear within its limits, let us have it in the simplest form, and conceive the atoms to be all of gold; then, I would fain learn by what step the hypothesis proposes to effect its passage to the chemical forces and their innumerable results. Heat it may manage to reach by the friction and compression of the materials at its disposal; and its metal universe may thus have its solid, liquid, and gaseous provinces; but, beyond these varieties, its homogeneous particles cannot advance the history one hair's breadth through an eternity. It is not true, then, that the conditions which give the first type of force suffice to promote it to the second; and in order to start the world on its chemical career, you must enlarge its capital and present it with an outfit of heterogeneous constituents. Try, therefore, the effect of such a gift; fling into the pre-existing caldron the whole list of recognized elementary substances, and give leave to their affinities to work: we immediately gain an immense accession to our materials for the architecture and resources for the changes of the world,—the water and the air, the salts of the ocean, and the earthy or rocky compounds that compose the crust of the globe, and the variable states of magnetism and heat, which throw the combinations into slow though constant change. But with all your enlargement of data, turn them as you will, at the end of every passage which they explore, the door of life is closed against them still; and though more than once it has been proclaimed that a way has been found through, it has proved that the living thing was on the wrong side to begin with. It is not true, therefore, that, from the two earlier stages of force, the ascent can be made to the vital level; the ethereal fire yet remains in Heaven; and philosophy has not stretched forth the Promethean arm that can bring it down. And if, once more, we make you a present of this third phase of power, and place at your disposal all that is contained beneath and within the flora of the world, still your problem is no easier than before; you cannot take a single step towards the deduction of sensation and thought: neither at the upper limit do the highest plants (the exogens) transcend themselves and overbalance into animal existence; nor at the lower, grope as you may among the sea-weeds and sponges, can you persuade the sporules of the one to develop into the other. It is again not true, therefore, that, in virtue of the convertibility of force, the possession of any is the possession of the whole: we give you all the forms but one; and that one looks calmly down on your busy evolutions, and remains inaccessible. Is, then, the transmigration of forces altogether an illusion? By no means; but before one can exchange with another, both must be there; and to turn their equivalence into a universal formula, all must be there. With only one kind of elementary matter, there can be no chemistry; with only the chemical elements and their laws, no life; with only vital resources, as in the vegetable world, no beginning of mind. But let Thought and Will with their conditions once be there, and they will appropriate vital power; as life, once in possession, will ply the alembics and the test-tubes of its organic laboratory; and chemical affinity is no sooner on the field than it plays its game among the cohesions of simple gravitation. Hence it is impossible to work the theory of Evolution upwards from the bottom. If all force is to be conceived as One, its type must be looked for in the highest and all-comprehending term; and Mind must be conceived as there, and as divesting itself of some specialty at each step of its descent to a lower stratum of law, till represented at the base under the guise of simple Dynamics. Or, if you retain the forces in their plurality, then you must assume them all among your data, and confess, with one of the greatest living expositors of the phenomena of Development, that unless among your primordial elements you scatter already the germs of mind as well as the inferior elements, the Evolution can never be wrought out.[15] But surely a theory, which is content simply to assume in the germ whatever it has to turn out full-grown, throws no very brilliant light on the genesis of the Universe.
[15] Lotze's Mikrokosmus, B. iv. Kap. 2, Band ii. 33, seqq.
ii. The second and principal support of the doctrine under review is found in the realm of natural history, and in that province of it which is occupied by living beings. Here, it is said, in the field of observation nearest to us, we have evidence of a power in each nature to push itself and gain ground, as against all natures less favorably constituted. There is left open to it a certain range of possible variations from the type of its present individuals, of which it may avail itself in any direction that may fortify its position; and even if its own instincts did not seize at once the line of greatest strength, still, out of its several tentatives, all the feeble results would fail to win a footing, and only the residuary successes would make good their ground. The ill-equipped troops of rival possibilities being always routed, however often they return, the well-armed alone are seen upon the field, and the world is in possession of "the fittest to live." We thus obtain a principle of self-adjusting adaptation of each being to its condition, without resorting to a designing care disposing of it from without; and its development is an experimental escape from past weakness, not a pre-conceived aim at a future perfection.