Part 2 (1/2)

Lastly, the argument is precisely the same as that which occurs in numerous pa.s.sages of Scripture and in theological writings all over the world down to the present time. That is to say, everywhere in organic nature we meet with innumerable adaptations of means to ends, which in very many cases present a degree of refinement and complexity in comparison with which the adaptations of means to ends in a watch are but miserable and rudimentary attempts at mechanism. No one can know so well as the modern biologist in what an immeasurable degree the mechanisms which occur in such profusion in nature surpa.s.s, in every form of excellence, the highest triumphs of human invention. Hence at first sight it does unquestionably appear that we could have no stronger or better evidence of purpose than is thus afforded. In the words of Paley: 'arrangement, disposition of parts, subserviency of means to an end, relation of instruments to a use, imply the presence of intelligence and mind.'

But next the question arises, Although such things certainly [may][22]

imply the presence of mind as their explanatory cause, are we ent.i.tled to a.s.sume that there can be in nature no other cause competent to produce these effects? This is a question which never seems to have occurred to Paley, Bell, Chalmers, or indeed to any of the natural theologians up to the time of Darwin. This, I think, is a remarkable fact, because the question is one which, as a mere matter of logical form, appears to lie so much upon the surface. But nevertheless the fact remains that natural theologians, so far as I know without exception, were satisfied to a.s.sume as an axiom that mechanism could have no cause other than that of a designing mind; and therefore their work was restricted to tracing out in detail the number and the excellency of the mechanisms which were to be met with in nature. It is, however, obvious that the mere acc.u.mulation of such cases can have no real, or logical, effect upon the argument. The mechanisms which we encounter in nature are so amazing in their perfections, that the attentive study of any one of them would (as Paley in his ill.u.s.tration virtually, though not expressly, contends) be sufficient to carry the whole position, if the a.s.sumption be conceded that mechanism can only be due to mind. Therefore the argument is not really, or logically, strengthened by the mere acc.u.mulation of any number of special cases of mechanism in nature, all as mechanisms similar in kind. Let us now consider this argument.

If we are disposed to wonder why natural theologians prior to the days of Darwin were content to a.s.sume that mind is the only possible cause of mechanism, I think we have a ready answer in the universal prevalence of their belief in special creation. For I think it is unquestionable that, upon the basis of this belief, the a.s.sumption is legitimate. That is to say, if we start with the belief that all species of plants and animals were originally introduced to the complex conditions of their several environments suddenly and ready made (in some such manner as watches are turned out from a manufactory), then I think we are reasonably ent.i.tled to a.s.sume that no conceivable cause, other than that of intelligent purpose, could possibly be a.s.signed in explanation of the effects. It is, of course, needless to observe that in so far as this previous belief in special creation was thus allowed to affect the argument from design, that argument became an instance of circular reasoning. And it is, perhaps, equally needless to observe that the mere fact of evolution, as distinguished from special creation--or of the gradual development of living mechanisms, as distinguished from their sudden and ready-made apparition--would not in any way affect the argument from design, unless it could be shown that the process of evolution admits the possibility of some other cause which is not admitted by the hypothesis of special creation. But this is precisely what is shown by the theory of evolution as propounded by Darwin. That is to say, the theory of the gradual development of living mechanisms propounded by Darwin, is something more than a theory of gradual development as distinguished from sudden creation. It is this, but it is also a theory of a purely scientific kind which seeks to explain the purely physical causes of that development. And this is the point where natural science begins to exert her influence upon natural theology--or the point where the theory of evolution begins to affect the theory of design. As this is a most important part of our subject, and one upon which an extraordinary amount of confusion at the present time prevails, I shall in my next paper carefully consider it in all its bearings.

FOOTNOTES:

[19] [The third paper is not published because Romanes' views on the relation between science and faith in Revealed Religion are better and more maturely expressed in the Notes.--ED.]

[20] To avoid misunderstanding I may observe that in the above definitions I am considering Religion and Science under the conditions in which they actually exist. It is conceivable that under other conditions these two departments of thought might not be so sharply separated. Thus, for instance, if a Religion were to appear carrying a revelation to Science upon matters of physical causation, such a Religion (supposing the revelation were found by experiment to be true) ought to be held to exercise upon Science a strictly legitimate influence.

[21] _Mental Evolution in Animals_, pp. 155-8.

[22] [I have put 'may' in place of 'do' for the sake of argument.--ED.]

II.

Suppose the man who found the watch upon a heath to continue his walk till he comes down to the sea-sh.o.r.e, and suppose further that he is as ignorant of physical geography as he is of watch-making. He soon begins to observe a number of adaptations of means to ends, which, if less refined and delicate than those that formed the object of his study in the watch, are on the other hand much more impressive from the greatly larger scale on which they are displayed. First, he observes that there is a beautiful basin hollowed out in the land for the reception of a bay; that the sides of this basin, which from being near its opening are most exposed to the action of large rolling billows, are composed of rocky cliffs, evidently in order to prevent the further encroachment of the sea, and the consequent destruction of the entire bay; that the sides of the basin, which from being successively situated more inland are successively less and less exposed to the action of large waves, are const.i.tuted successively of smaller rocks, pa.s.sing into s.h.i.+ngle, and eventually into the finest sand: that as the tides rise and fall with as great a regularity as was exhibited by the movements of the watch, the stones are carefully separated out from the sand to be arranged in sloping layers by themselves, and this always with a most beautiful reference to the places round the margin of the basin which are most in danger of being damaged by the action of the waves. He would further observe, upon closer inspection, that this process of selective arrangement goes into matters of the most minute detail. Here, for instance, he would observe a mile or two of a particular kind of seaweed artistically arranged in one long sinuous line upon the beach; there he would see a wonderful deposit of sh.e.l.ls; in another place a lovely little purple heap of garnet sand, the minute particles of which have all been carefully picked out from the surrounding acres of yellow sand.

Again, he would notice that the streams which come down to the bay are all flowing in channels admirably dug out for the purpose; and, being led by curiosity to investigate the teleology of these various streams, he would find that they serve to supply the water which the sea loses by evaporation, and also, by a wonderful piece of adjustment, to furnish fresh water to those animals and plants which thrive best in fresh water, and yet by their combined action to carry down sufficient mineral const.i.tuents to give that precise degree of saltness to the sea as a whole which is required for the maintenance of pelagic life. Lastly, continuing his investigations along this line of inquiry, he would find that a thousand different habitats were all thoughtfully adapted to the needs of a hundred thousand different forms of life, none of which could survive if these habitats were reversed. Now, I think that our imaginary inquirer would be a dull man if, as the result of all this study, he failed to conclude that the evidence of Design furnished by the marine bay was at least as cogent as that which he had previously found in his study of the watch.

But there is this great difference between the two cases. Whereas by subsequent inquiry he could ascertain as a matter of fact that the watch was due to intelligent contrivance, he could make no such discovery with reference to the marine bay: in the one case intelligent contrivance as a cause is independently demonstrable, while in the other case it can only be inferred. What, then, is the value of the inference?

If, after the studies of our imaginary teleologist had been completed, he were introduced to the library of the Royal Society, and if he were then to spend a year or two in making himself acquainted with the leading results of modern science, I fancy that he would end by being both a wiser and a sadder man. At least I am certain that in learning more he would feel that he is understanding less--that the archaic simplicity of his earlier explanations must give place to a matured perplexity upon the whole subject. To begin with, he would now find that every one of the adjustments of means to ends which excited his admiration on the sea-coast were due to physical causes which are perfectly well understood. The cliffs stood at the opening of the bay because the sea in past ages had encroached upon the coast-line until it met with these cliffs, which then opposed its further progress; the bay was a depression in the land which happened to be there when the sea arrived, and into which the sea consequently flowed; the successive occurrence of rocks, s.h.i.+ngle, and sand was due to the actions of the waves themselves; the segregation of sea-weeds, sh.e.l.ls, pebbles, and different kinds of sand, was due to their different degrees of specific gravity; the fresh-water streams ran in channels because they had themselves been the means of excavating them; and the mult.i.tudinous forms of life were all adapted to their several habitats simply because the unsuited forms were not able to live in them. In all these cases, therefore, our teleologist in the light of fuller knowledge would be compelled to conclude at least this much--that the adaptations which he had so greatly admired when he supposed that they were all due to contrivance in antic.i.p.ation of the existing phenomena, cease to furnish the same evidence of intelligent design when it is found that no one of them was prepared beforehand by any independent or external cause.

He would therefore be led to conclude that if the teleological interpretation of the facts were to be saved at all, it could only be so by taking a much wider view of the subject than was afforded by the particular cases of apparent design which at first appeared so cogent.

That is to say, he would feel that he must abandon the supposition of any _special_ design in the construction of that particular bay, and fall back upon the theory of a much more _general_ design in the construction of one great scheme of Nature as a whole. In short he would require to dislodge his argument from the special adjustments which in the first instance appeared to him so suggestive, to those general laws of Nature which by their united operation give rise to a cosmos as distinguished from a chaos.

Now I have been careful thus to present in all its more important details an imaginary argument drawn from inorganic nature, because it furnishes a complete a.n.a.logy to the actual argument which is drawn from organic nature. Without any question, the instances of apparent design, or of the apparently intentional adaptation of means to ends, which we meet with in organic nature, are incomparably more numerous and suggestive than anything with which we meet in inorganic nature. But if once we find good reason to conclude that the former, like the latter, are all due, not to the immediate, special and prospective action of a contriving intelligence (as in watch-making or creation), but to the agency of secondary or physical causes acting under the influence of what we call general laws, then it seems to me that no matter how numerous or how wonderful the adaptations of means to ends in organic nature may be, they furnish one no other or better evidence of design than is furnished by any of the facts of inorganic nature.

For the sake of clearness let us take any special case. Paley says, 'I know of no better method of introducing so large a subject than that of comparing a single thing with a single thing; an eye, for example, with a telescope.' He then goes on to point out the a.n.a.logies between these two pieces of apparatus, and ends by asking, 'How is it possible, under circ.u.mstances of such close affinity, and under the operation of equal evidence, to exclude contrivance in the case of the eye, yet to acknowledge the proof of contrivance having been employed, as the plainest and clearest of all propositions in the case of the telescope?'

Well, the answer to be made is that only upon the hypothesis of special creation can this a.n.a.logy hold: on the hypothesis of evolution by physical causes the evidence in the two cases is _not_ equal. For, upon this hypothesis we have the eye beginning, not as a ready-made structure prepared beforehand for the purposes of seeing, but as a mere differentiation of the ends of nerves in the skin, probably in the first instance to enable them better to discriminate changes of temperature.

Pigment having been laid down in these places the better to secure this purpose (I use teleological terms for the sake of brevity), the nerve-ending begins to distinguish between light and darkness. The better to secure this further purpose, the simplest conceivable form of lens begins to appear in the shape of small refractive bodies. Behind these sensory cells are developed, forming the earliest indication of a retina presenting a single layer. And so on, step by step, till we reach the eye of an eagle.

Of course the teleologist will here answer--'The fact of such a gradual building up is no argument against design: whether the structure appeared on a sudden or was the result of a slow elaboration, the marks of design in either case occur in the structure as it stands.' All of which is very true; but I am not maintaining that the fact of a gradual development _in itself_ does affect the argument from design. I am maintaining that it only does so because it reveals the possibility (excluded by the hypothesis of sudden or special creation) of the structure having been proximately due to the operation of physical causes. Thus, for the value of argument, let us a.s.sume that natural selection has been satisfactorily established as a cause adequate to account for all these effects. Given the facts of heredity, variation, struggle for existence, and the consequent survival of the fittest, what follows? Why that each step in the prolonged and gradual development of the eye was brought about by the elimination of all the less adapted structures in any given generation, i.e. the selection of all the better adapted to perpetuate the improvement by heredity. Will the teleologist maintain that this selective process is itself indicative of special design? If so, it appears to me that he is logically bound to maintain that the long line of seaweed, the sh.e.l.ls, the stones and the little heap of garnet sand upon the sea-coast are all equally indicative of special design. The general laws relating to specific gravity are at least of as much importance in the economy of nature as are the general laws relating to specific differentiation; and in each ill.u.s.tration alike we find the result of the operation of known physical causes to be that of selection. If it should be argued in reply that the selection in the one case is obviously purposeless, while in the other it is as obviously purposive, I answer that this is pure a.s.sumption. It is perhaps not too much to say that every geological formation on the face of the globe is either wholly or in part due to the selective influence of specific gravity, and who shall say that the construction of the earth's crust is a less important matter in the general scheme of things (if there is such a scheme) than is the evolution of an eye? Or who shall say that because we see an apparently intentional adaptation of means to ends as the result of selection in the case of the eye, there is no intention served by the result of selection in the case of the sea-weeds, stones, sand, mud? For anything that we can know to the contrary, the supposed intelligence may take a greater delight in the latter than in the former process.

For the sake of clearness I have a.s.sumed that the physical causes with which we are already acquainted are sufficient to explain the observed phenomena of organic nature. But it clearly makes no difference whether or not this a.s.sumption is conceded, provided we allow that the observed phenomena are all due to physical causes of some kind, be they known or unknown. That is to say, in whatever measure we exclude the hypothesis of the direct or immediate intervention of the Deity in organic nature (miracle), in that measure we are reducing the evidence of design in organic nature to precisely the same logical position as that which is occupied by the evidence of design in inorganic nature. Hence I conceive that Mill has shown a singular want of penetration where, after observing with reference to natural selection, 'creative forethought is not absolutely the only link by which the origin of the wonderful mechanism of the eye may be connected with the fact of sight,' he goes on to say, 'leaving this remarkable speculation (i.e. that of natural selection) to whatever fate the progress of discovery may have in store for it, in the present state of knowledge the adaptations in nature afford a large balance of probability in favour of creation by intelligence.' I say this pa.s.sage seems to me to show a singular want of penetration, and I say so because it appears to argue that the issue lies between the hypothesis of special design and the hypothesis of natural selection. But it does not do so. The issue really lies between special design and natural causes. Survival of the fittest is one of these causes which has been suggested, and shown by a large acc.u.mulation of evidence to be probably a true cause. But even if it were to be disproved as a cause, the real argumentative position of teleology would not thereby be effected, unless we were to conclude that there can be no other causes of a secondary or physical kind concerned in the production of the observed adaptations.

I trust that I have now made it sufficiently clear why I hold that if we believe the reign of natural law, or the operation of physical causes, to extend throughout organic nature in the same universal manner as we believe this in the case of inorganic nature, then we can find no better evidence of design in the one province than in the other. The mere fact that we meet with more numerous and apparently more complete instances of design in the one province than in the other is, _ex hypothesi_, merely due to our ignorance of the natural causation in the more intricate province. In studying biological phenomena we are all at present in the intellectual position of our imaginary teleologist when studying the marine bay: we do not know the natural causes which have produced the observed results. But if, after having obtained a partial key in the theory of natural selection, we trust to the large a.n.a.logy which is afforded by the simpler provinces of Nature, and conclude that physical causes are everywhere concerned in the production of organic structures, then we have concluded that any evidence of design which these structures present is of just the same logical value as that which we may attach to the evidence of design in inorganic nature. If it should still be urged that the adaptations met with in organic nature are from their number and unity much more suggestive of design than anything met with in inorganic nature, I must protest that this is to change the ground of argument and to evade the only point in dispute.

No one denies the obvious fact stated: the only question is whether any number and any quant.i.ty of adaptations in any one department of nature afford other or better evidence of design than is afforded by adaptations in other departments, when all departments alike are supposed to be equally the outcome of physical causation. And this question I answer in the negative, because we have no means of ascertaining the extent to which the process of natural selection, or any other physical cause, is competent to produce adaptations of the kind observed.

Thus, to take another instance of apparent design from inorganic nature, it has been argued that the const.i.tution of the atmosphere is clearly designed for the support of vegetable and animal life. But before this conclusion can be established upon the facts, it must be shown that life could exist under no other material conditions than those which are furnished to it by the elementary const.i.tuents of the atmosphere. This, however, it is clearly impossible to show. For anything that we can know to the contrary, life may actually be existing upon some of the other heavenly bodies under totally different conditions as to atmosphere; and the fact that on this planet all life has come to be dependent upon the gases which occur in our atmosphere, may be due simply to the fact that it was only the forms of life which were able to adapt themselves (through natural selection or other physical causes) to these particular gases which could possibly be expected to occur--just as in matters of still smaller detail, it was only those forms of life that were suited to their several habitats in the marine bay, which could possibly be expected to be found in these several situations. Now, if a set of adjustments so numerous and so delicate as those on which the relations of every known form of life to the const.i.tuent gases of the atmosphere are seen to depend, can thus be shown not necessarily to imply the action of any disposing intelligence, how is it possible to conclude that any less general exhibitions of adjustment imply this, so long as every case of adjustment, whether or not ultimately due to design, is regarded as proximately due to physical causes?

In view of these considerations, therefore, I think it is perfectly clear that if the argument from teleology is to be saved at all, it can only be so by s.h.i.+fting it from the narrow basis of special adaptations, to the broad area of Nature as a whole. And here I confess that to my mind the argument does acquire a weight which, if long and attentively considered, deserves to be regarded as enormous. For, although this and that particular adjustment in Nature may be seen to be proximately due to physical causes, and although we are prepared on the grounds of the largest possible a.n.a.logy to infer that all other such particular cases are likewise due to physical causes, the more ultimate question arises, How is it that all physical causes conspire, by their united action, to the production of a general order of Nature? It is against all a.n.a.logy to suppose that such an end as this can be accomplished by such means as those, in the way of mere chance or 'the fortuitous concourse of atoms.' We are led by the most fundamental dictates of our reason to conclude that there must be some cause for this co-operation of causes.

I know that from Lucretius' time this has been denied; but it has been denied only on grounds of _feeling_. No possible _reason_ can be given for the denial which does not run counter to the law of causation itself. I am therefore perfectly clear that the only question which, from a purely rational point of view, here stands to be answered is this--Of what nature are we to suppose the _causa causarum_ to be?

On this point only two hypotheses have ever been advanced, and I think it is impossible to conceive that any third one is open. Of these two hypotheses the earliest, and of course the most obvious, is that of mental purpose. The other hypothesis is one which we owe to the far-reaching thought of Mr. Herbert Spencer. In Chapter VII of his _First Principles_ he argues that all causation arises immediately out of existence as such, or, as he states it, that 'uniformity of law inevitably follows from the persistence of force.' For 'if in any two cases there is exact likeness not only between those most conspicuous antecedents which we distinguish as the causes, but also between those accompanying antecedents which we call the conditions, we cannot affirm that the effects will differ, without affirming either that some force has come into existence or that some force has ceased to exist. If the co-operative forces in the one case are equal to those in the other, each to each, in distribution and amount; then it is impossible to conceive the product of their joint action in the one case as unlike that in the other, without conceiving one or more of the forces to have increased or diminished in quant.i.ty; and this is conceiving that force is not persistent.'