THE DUKE OF ARGYLL ON THE REIGN OF LAW.* This

is in its way a masterly book,—not a book of many ideas, hit of a few very ably and powerfully put, by a man who has a real and accurate knowledge of many departments of natural history. It is the first from any Cabinet Minister of standing on the philo- sophy of science, and it shows, we think, almost as large a power of thought and as strong a judgment within its sphere as any of Sir Cornewall Lewis's books, and more than many of Mr. Gladstone's, who has not always chosen for literary discussion sub- jects for the treatment of which his genius is as well adapted as it is for great political efforts. Nothing can be abler than the way in which the Duke of Argyll disentangles and illustrates the various uses of the word "Law "in its scientific sense, and shows how much it really means, what false meanings have been put upon it, and what are the scientific reasons for rejecting those false meanings. It is his inference after long and close discussion that 'Law' in the scientific sense not only does not exclude the idea that Will and knowledge lie behind it, and use it as a means, even in the case of simple invariable forces, like gravity, but compels us to the assumption of such Will and knowledge in relation to all the higher and more composite results of Law. Here is the Duke of Argyll's main result stated with admirable force and clearness :— "There is no observed order of facts which is not due to a combina- tion of forces ; and there is no combination of forces which is invariable—none which is not capable of change in infinite degrees. In these senses—and these are the common senses in which Law is used to express the phenomena of Nature—Law is not rigid, it is not immut- able, it is not invariable, but it is, on the contrary, pliable, subtle, various. In the only sense in which laws are immutable this immut- ability is the very characteristic which makes them subject to guidance through endless cycles of design. We know this in our own case. It is the very certainty and invariableness of the laws of nature which alone enable us to use them, and to yoke them to our service. Now, the laws of nature are employed in the system of nature in a manner precisely analogous to that in which we ourselves employ them. The difficulties and obstructions which are presented by one law in the way of accomplishing a given purpose, are met and overcome exactly on the same principle on which they are met and overcome by man,—viz. by knowledge of other laws, and by resource in applying them —thal is by ingenuity in mechanical contrivance. It cannot be too much insisted on, that this is a conclusion of pure science. The relation which an organic structure bears to its purpose in nature can be recognized as certainly as the same relation between a machine and its purpose in human art. It is absurd to maintain, for example, that the purpose of the cellular arrangement of material in combining lightness with strength is a purpose legitimately cognizable by Science in the Menai Bridge, but is not as legitimately cognizable when it is seen in nature, actually serving the same use. The little barnacles which crust the rocks at low tide, and which to live there at all must be able to resist the surf, have the building of their shells constructed strictly with reference to this necessity. It is a structure all hollowed and chambered on the plan which engineers have so lately discovered as an arrangement of material by which the power of resisting strain or pressure is multiplied in an extraordinary degree. That shell is as pure a bit of mechanics as the bridge, both being structures in which the same arrangement is adapted to the same end.

Small, but a work divine ; Frail, but of force to withstand ; Year upon year, the shock Of cataract seas that snap The three-decker's oaken spine.'

This is but one instance out of a number which no man can count. So far as we know, no law—that is, no elementary force—of nature is liable to change. But every law of nature is liable to counteraction ; and the rule is, that laws are habitually made to counteract each other in precisely the manner and degree which some definite result re- quires."

Nothing can be better than the illustration which the Duke gives of the infinitely varied use made of invariable forces in the phenomena of the flight of birds by the combined counteraction and use of the power of gravity, without the direct operation of which on bodies, themselves specifically much heavier than air, no self-guidance like that of birds would be possible. The chapter on "Contrivance a Necessity arising out of the Reign of Law" is,

• The Reign of Law. By the Duke of ArgylL London; Strahan.

though conceived of course in the same general tone as Paley's Natural Theology, much better adapted in its detail to the larger modern philosophy of science, which in Paley's time was scarcely yet saturated with the notion of invariable and immutable law in the way in which the science of our own age has been saturated with it.

In Paley's time 'contrivance' was looked upon as the most certain, and natural indication of a divine origin for the world. In our- own, 'contrivance' has been rather regarded as the •intermediate mode of art proper to the poverty of human resources,—inter- mediate, we mean, between the more liberal inspiration of the creative processes which are supposed in the vast wealth of' their divine art to have no occasion to accommodate anxiously means to ends, and the helplessness of creatures living amongst. conditions which they must simply accept, and cannot in any degree modify. It is in most respects an access of wonder and awe at the vastness and fertility of the creative processes, and a growing humility of tone with regard to human inventions, which has caused this depreciating tone in speaking of Paley's demon- strations of divine contrivance. The tendency has been more pantheistic than atheistic—more to speak of the art of creation as. something infinitely beyond the style of providential ' contrivance ' such as Paley delineated it, than to deny an intellectual and moral order to the constitution of the universe. The Duke of Argyll does not lower his tone in speaking of the wonderful constitution of the natural world to that mere admiration of external ingenuities which marks the architectural and mechanical similitudes of Paley. He does not evidently think of the world as a very beautiful and complicated watch, with innumerable compensated balances, as Paley sometimes seems to do. But he does show us. very clearly that that very characteristic of absolute invariability belonging to the distinct forces which are at the foundations of the physical universe,—a characteristic which is so much insisted on as heightening the grandeur of Nature,—compels us to per- ceive the contriving purpose at work behind those forces, com- bining, counteracting, and balancing them with a variety and delicacy of purpose productive of results at first sight quite inconsistent with what we regard as invariable laws whets looking only at the separate elements. "We feel, some- times," says the Duke of Argyll, "as if it were an unworthy notion of the Will which works in nature to suppose that it.

should never act except through the use of means. But our notions of unworthiness are themselves often the unworthiest.

of all It seems as if all that is done in Nature as well as all that is done in Art is done by knowing how to. do it." And this "knowing how to do it," when the difference between doing it and not doing it depends on the slightest pos- sible variation in the conditions under which forces in themselves. absolutely immutable, and, when once applied, absolutely certain in their operation, are brought to bear, may properly be called.

'contrivance,' even though the vast variety of the creative- processes show that there is none of the limitation about divine contrivance that there is about human mechanism,—that.

the same result may be accomplished by a thousand different.

modes in the organic system of the universe, though human in- genuity is fairly honoured as triumphant if it can imitate imper- fectly but one. The essence of 'contrivance' consists not in the limitation of the resources at disposal, but in that delicate fit of means to ends, where the slightest variation would ensure failure, which betrays foreknowledge and purpose. No illustration of this could be better than the one selected by our author in that.

mechanism of ffight, in different species of birds, the varieties of which he has sketched with the knowledge of a true naturalist. The Duke maintains that the doctrine of ' purpose ' or 'contriv-

ance' in nature is leas truly transcendental, less merely a matter of ideal hypothesis, than the doctrine of the comparative anatomists that certain organs in one animal are the 'homologues,'.—that is, occupy the same place in relation to a scientific theory of the skeleton,—of certain other organs in other animals :— "Even as a general doctrine, the doctrine of Contrivance and Adjust- ment in not so metaphysical as the doctrine of Homologies ; and when we come to particular cases there can be no question whatever that the relation of a given structure to its purpose and function comes MOTO unequivocally under the class Of physical facts than the relation to that same structure to some corresponding part in another animal. It is less ideal, for example,—lesa theoretical—less metaphysical—to assert of the little hooked claw which is attached to the (apparent) elbow of a bat's wing, that it was placed there to enable the bat to climb and crawl, than to affirm of that same claw that it is the homologue of the human thumb. Yet who can deny that this doctrine of Homologies has been established as a strictly scientific truth ? There is a sense, of course, in which all knowledge and all science belongs to metaphysics. Mere classification, which is the basis of all science, what is it but the marshalling of phy- sical facts in an ideal order—an arrangement of them according to the relation which they bear to the laws of thought ? Bat this does not

constitute as a branch of metaphysics the division of animals into genera, and families, and orders. And what relation can physical facts ever have to thought so directly cognizable or so susceptible of demon- stration as the relation of an animal organ to its purpose and function in the animal economy ? Whether purpose be the basis of all natural order or not is a separate question. It is at least one of the facts of that order. Combination for the accomplishment of purpose therefore in particular cases, such as the relation between the structure of an organ and its function, is not merely a safe conclusion of philosophy, but an ascertained fact of science."

The only answer to this reasoning,—which seems to us abso- lutely just,—would be to say that the doctrine of correspond- ences between one organ and another may be regarded by any one who denies an intellectual plan to the universe as a mere mode of indicating similarities of structure as they are perceived by us when we begin to map out the universe, and possibly due to like causes, but not necessarily as proving a preconceived similarity of plan or purpose ;—just as we might say that the pointed shapes of the great continental peninsulas

of South America, Africa, and India, are necessarily classified together by us from their striking similarities of form, and re- ferred with some probability to similar physical causes, but not necessarily referred to one common intellectual cause behind the common physical causes. On the other hand, though the actual function of an organ is a matter of science, to say that this is its purpose as well as its function, supposes that it was made with this special intent, which is of course true, but not proved to be true by the fact that the purpose, if existing, would be by it successfully carried into effect. To prove this we ought to be able to show that an organ so admirably suited to fulfil such a function could not

reasonably be ascribed to anything but an intelligent selection of means to ends. Now, this is what Mr. Darwin's theory of natural selection' is supposed by some to refute. And the only weakness of the Duke of Argyll's book seems to us to be that it does not deal adequately with the negative side of Mr. Darwin's theory as it is understood by many, except only on one point. His ehapter on the failure of Mr. Darwin's theory to account for the distinct purposes of non-utilitarian beauty and variety discernible in the constitution of Nature, is admirable and complete. But

on the side on which it professes to account for the existence of so many wonderfully perfect organisms, without assuming that such organisms were more expressly provided for than a host of other very imperfect or even wholly manques organisms in the original manufactory of nature, the Duke of Argyll scarcely meets it fairly. He remarks to some extent justly:— "If, then, it be true that new species are created out of small varia- tions in the form of old species, and this by way of natural generation, there mast be some bond of connection which determines those varia- tions in a definite direction, and keeps up the external correlations pani passu with the internal correlations. Natural selection can have no part in this. Natural selection seizes on these external correlations when they have come to be. But natural selection cannot enter the taxi et chambers of the womb, and there shape the new form in harmony with modified conditions of external life. How, then, are these external correlations provided for beforehand ? There can be but one reply. It is by utility, not acting as a physical cause upon organs already in existence, but acting through motive as a mental purpose in contriving organs before they have begun to be. And where obvious utility does result, the only connecting bond which can be conceived as capable of maintaining the internal correlations in harmony with the external correlations, is the bond of creative Will giving to organic forces a fore- seen direction_ It is, in short, precisely the same bond which in all mechanism produces harmony of structure with intended function."

But then, in pointing out here the complete inadequacy of the Darwinian theory to account for any specific modification at all, or to do anything but explain why one species multiplies where another dies out, the Duke does not fairly represent the painful conception

-which Darwin's theory suggests of the origin of the universe to those who brood upon it most. It is true that all that Mr. Darwin has established is that, in some important eases, the species which has prospered has driven out the species which has not prospered, by virtue of some physical advantage which it has over it in the " con- flict for existence." But he has summoned up a picture much more general, of a purely tentative Nature, trying all experiments bad and good, creating fifty different organisms which are not suited to the world in which they are produced to every one which is, though that one alone multiplies and alone leaves traces of its former existence to future generations. It is as if a mathematician should write down all possible permutations and combinations to be made out of the twenty-six letters of the alphabet, and then some power unknown were to throw aside the unmeaning and unpro- nounceable words to be used no more, and register the others for ever in our language. The gibberish would not survive, while the

other useful words would be used a thousand times by each subse- quent author till they left indelible traces in our literature. So

Mr. Darwin's theory suggests that Nature may possibly have tried

an infinite number of unsuccessful experiments for every experi- ment that lives and can multiply itself ,—and no doubt if this were so, the moral impression left on the mind by the birth of number- less &soars:: for every cosmos, of hundreds of animals that could not live or reproduce themselves for every one that can, would be very different indeed from the impression we all have of Nature choosing with unerring aim, in the strength of her divine wisdom, the very groove within which her career is certain to be great and productive. Suppose Nature had originally made ten birds with wings too clumsy to fly for every bird that could fly,—a hundred that had a taste for poisonous berries to one that liked only

wholesome berries,—several species of bees in countries where there was no honey, and several kinds of grass-eating crea- tures in deserts without a blade of grass, and that all these had disappeared wholly from our survey simply because in the nature of things they could not multiply,—should we and could we talk of the Providence in 'natural selection' as those who believe in Mr. Darwin's facts, but ascribe them to divine purpose, are in the

habit of doing? Surely not. We should regard the real universe as the one prize in a lottery all the rest of which were blanks, and should regard the ultimate cause as quite as fairly represented in

the failures as in the successes.

The Duke of Argyll does not face this dreary suggestion of Mr.

Darwin's theory at all, and, therefore, only incidentally gives a reply to it which, so far as it goes, is effective. He says "beauty" Las clearly not, in many cases at least, the least tendency to per- petuate a species by giving it any advantage in the conflict for existence, and yet beauty, beauty of the highest kind, is certainly

a part of the law of the existence of many species of creatures far too minute ever to meet the human eye, as well as of others, like humming birds, which do :— "Nowhere is ornament more richly given, nowhere is it seen more separate from the use, than in those organisms of whose countless mil- lions the microscope alone enables a few men for a few momenta to see a few examples. There is no better illustration of this than a class of forms belonging to the border-land of animal and vegetable life called the Diatomacem, which, though invisible to the naked eye, play an impor- tant part in the economy of nature. They exist almost everywhere, and of their remains whole strata, and even mountains, are in great part composed. They have shells of pure sib; and these, each after its own kind, are all covered with the most elaborate ornament—striated, or fluted, or punctured, or dotted in patterns which are mere patterns, but patterns of perfect, and sometimes of most complex beauty. No graving done with the graver's tool can equal that work in gracefulness of design, or in delicacy and strength of touch. Yet it is impossible to look at these forms—in all the variety which is often crowded under a single lens— without recognizing instinctively that the work of the graver is work strictly analogous, —addressed to the same perceptions,—founded on the same idea,—having for its object the same end and aim. And as the work of the graver varies for the mere sake of varying, so does the work on these microscopic shells. In the same drop of moisture there may be some dozen or twenty forms, each with its own distinctive pattern, all as constant as they are distinctive, yet having all apparently the same habits, and without any perceptible difference of function."

But there is another answer which the Duke has not given,— that Mr. Darwin's theory requires a law of hereditary genera- tion transmitting the (accidentally favourable) variations on species before it can come into action at all. Now, in nothing is the previous organic provision more curious and remarkable than in the ease of this law itself which Mr. Darwin is obliged to assume. Thus, as every one knows, there is a fly, the female of which is the glowworm, a creature of a different sort, and the provision which multiplies the species must provide for the recognition of the glowworm by the fly as the female of its own species. Hence, before the law of selection by special transmission of qualities favourable to prolong life can come into operation at all, a law itself requiring design of the highest order must have produced the apparatus for hereditary trans- mission in this, as in other cases. Mr. Darwin's theory is not

inconsistent with the conception of a tentative nature that, after she has got the law of hereditary transmission, might fail a hun- dred times for every success. But it is inconsistent with any attempt to produce the law of hereditary transmission,—itself one of the most wonderful cases of deaign,—out of a series of previous failures.

We have no space to follow the Duke of Argyll into "Law in the Realm of Mind," and the admirable chapter on "Law in Politics." In the former chapter we doubt whether he gets to the bottom of the question of free-will, as he does not fairly face the question whether volition can be traced completely back to any influences independent of will, like wishes, likings, motiVes, &c., in which case it would not be free, but determined wholly by

the influences (external or internal) which act upon the will. The last chapter of all is ad exceedingly thoughtful and masterly essay on the extent to which natural law should be accepted as the guiding rule of politics. The book is strong, sound, mature, able thought, from its first page to its last.