There is a good deal here which is less clear in the way of argument than could be wished. The famous Law of Substance, as we have seen, has two articles: The indestructibility of matter, and the conservation of energy. What light either of these principles may be supposed to shed on such questions as the adaptation of organs to their functions is by no means obvious. To say that there is no design in the organic world, because it is a special result of biological agencies,—is quite of a piece with the contention which has actually been made, that we can no longer argue to Design, with Paley, from the analogy of a watch, since "nearly every part of a watch is now made by inanimate machinery."[158] Thus much, however, is perfectly clear: the competence of Chance is recognized to originate a world like ours, and to enable Nature, as Professor Clifford says, seemingly[{119}] to answer our questionings with an intelligence akin to our own.
It would thus appear that when Newton asks,—Was the eye fashioned without knowledge of the laws of light, or the ear, without knowledge of those of sound?—we are to answer in the affirmative, and to say that such organs are but special results of biological agencies, under the general management of the Law of Substance.
That such a reply cannot with any truth be termed scientific is plain—for it touches matters which by her own acknowledgment Science cannot reach;—nor does it seem probable that this kind of talk would convince anybody, were there nothing more. Undoubtedly those who persuade themselves that the Order of the Universe can be sufficiently explained without introducing the idea of purpose or design, are influenced by other considerations than these.
(1) With some it is the argument, which appears chiefly to have weighed with Mr. Darwin, who constantly speaks of it as the great obstacle to that belief in Design which the marvels of the universe would otherwise necessitate. This he based on certain features in Nature which appeared to him incompatible with the work of a beneficent Author, mainly the existence of suffering amongst animals in whose case it cannot be supposed to subserve any purpose of moral benefit. As he wrote to Asa Gray:[159][{120}]
I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice. Not believing this, I see no necessity in the belief that the eye was expressly designed.
Such a mode of meeting the arguments for Design, though only indirect, undoubtedly deserves serious consideration, touching as it does the darkest of all mysteries—the Origin of Evil. It is clear, however, that in Mr. Darwin's case, and probably in that of many others, its effect was due in no slight degree to imagination rather than to reason. He picks out one or two instances of seeming cruelty in Nature, as though they were something exceptional, and appears to imply that they create an obstacle to a belief which Nature as a whole almost forces upon him. In reality, the same sort of thing goes on everywhere. Animal life from beginning to end is a record of rapine and slaughter, as Tennyson declared in a verse too trite to bear quotation. The most petted of pet dogs has no more compunction than a tiger in worrying creatures weaker than itself, and a robin-redbreast takes far more lives daily than does a sparrow-hawk. But to draw from these facts such large conclusions—is quite another matter. Can we imagine that we are qualified by[{121}] the fulness of our knowledge to pronounce judgment and declare that there can be no good end where we fail to perceive one? As Mr. Darwin admits in the very same passage: "I feel most deeply that the whole subject is too profound for the human intellect. A dog might as well speculate on the mind of Newton."
How much is there in the actions of persons much lowlier than Newton which to the most intelligent of animals, dogs, elephants, or monkeys, could they speculate at all, must seem wholly devoid of sense;—as for instance that men should spend such continual labour in digging and ploughing. So again, in his famous lecture on Coal, Professor Huxley depicts what might have been the reflections of a giant reptile of the Carboniferous Epoch, suggested by the seemingly senseless waste of nature's powers in the production of the primeval forests, that have furnished the coal measures, to which so much of our progress and civilization is directly due.
And, after all, given the universal law of death for all living things, it would hardly appear that we can assure ourselves that any attendant circumstance constitutes a greater evil—as Mr. Darwin's argument seems to assume; and yet, it does not appear ever to have been argued that there can be no purpose in Nature since no organic life endures for ever. Most probably, if we knew enough, we should plainly see that nothing could be more cruel than to have omitted the carnivora from creation, leaving herbivorous animals to multiply till they[{122}] starved one another to death, or at least to perish of senile decay far more painfully than under the fangs of tigers and wolves. Instances might moreover be quoted which serve to remind us how impossible it is rightly to estimate the true character of suffering amongst creatures altogether different from ourselves. Thus when, as eye-witnesses report, young scorpions clinging to their mother devour her alive, scientifically avoiding as long as possible all vital parts and mortal wounds—we are inclined to consider them monsters of wickedness, and their parent as a model of motherly devotion, whose sufferings cannot be less horrible than those of a caterpillar similarly eaten by the ichneumon grub. But we cannot with any reason impute more moral blame to the young scorpions, than to the lambkins which draw sustenance from their dams in another fashion which we find touching and poetical; while as for the mother—who doubtless treated her own parent in just the same fashion—she exhibits no symptom to show that she resents her offsprings' advances, any more than does the ewe, but on the contrary has her sting ever ready for any one who would interfere with them.
(2) It is a still more common objection to the doctrine of purpose everywhere in Nature, that such an idea is negatived by the continuity and uniformity of natural laws, precluding the notion of constant interference by another, supernatural, Agent. But this objection is based upon an entire misconception. No one imagines such intervention,[{123}] or that purpose guides nature as a pilot guides a ship by repeated orders to the man at the wheel. Undoubtedly the reign of law in nature is uninterrupted, but in that law purpose is interwoven as the controlling element; just as the mind of Homer governs the hand of every printer who sets up type for a new edition of the Iliad.
(3) Finally, there is the argument, already alluded to, that inasmuch as the most complex structures are daily transmitted under our eyes by generation, we have evidence that nature can produce them from her own resources, and by the operation of a merely natural law, such as no one doubts generation to be.