We regret to find ourselves compelled to dissent very widely from many of Professor Kolliker"s remarks; and from none more thoroughly than from those in which he seeks to define what we may term the philosophical position of Darwinism.
"Darwin," says Professor Kolliker, "is, in the fullest sense of the word, a Teleologist. He says quite distinctly (First Edition, pp. 199, 200) that every particular in the structure of an animal has been created for its benefit, and he regards the whole series of animal forms only from this point of view."
And again:
"7. The teleological general conception adopted by Darwin is a mistaken one.
"Varieties arise irrespectively of the notion of purpose, or of utility, according to general laws of Nature, and may be either useful, or hurtful, or indifferent.
"The a.s.sumption that an organism exists only on account of some definite end in view, and represents something more than the incorporation of a general idea, or law, implies a one-sided conception of the universe.
a.s.suredly, every organ has, and every organism fulfils, its end, but its purpose is not the condition of its existence. Every organism is also sufficiently perfect for the purpose it serves, and in that, at least, it is useless to seek for a cause of its improvement."
It is singular how differently one and the same book will impress different minds. That which struck the present writer most forcibly on his first perusal of the "Origin of Species" was the conviction that Teleology, as commonly understood, had received its deathblow at Mr. Darwin"s hands. For the teleological argument runs thus: an organ or organism (A) is precisely fitted to perform a function or purpose (B); therefore it was specially constructed to perform that function. In Paley"s famous ill.u.s.tration, the adaptation of all the parts of the watch to the function, or purpose, of showing the time, is held to be evidence that the watch was specially contrived to that end; on the ground, that the only cause we know of, competent to produce such an effect as a watch which shall keep time, is a contriving intelligence adapting the means directly to that end.
Suppose, however, that any one had been able to show that the watch had not been made directly by any person, but that it was the result of the modification of another watch which kept time but poorly; and that this again had proceeded from a structure which could hardly be called a watch at all--seeing that it had no figures on the dial and the hands were rudimentary; and that going back and back in time we came at last to a revolving barrel as the earliest traceable rudiment of the whole fabric.
And imagine that it had been possible to show that all these changes had resulted, first, from a tendency of the structure to vary indefinitely; and secondly, from something in the surrounding world which helped all variations in the direction of an accurate time-keeper, and checked all those in other directions; then it is obvious that the force of Paley"s argument would be gone. For it would be demonstrated that an apparatus thoroughly well adapted to a particular purpose might be the result of a method of trial and error worked by unintelligent agents, as well as of the direct application of the means appropriate to that end, by an intelligent agent.
Now it appears to us that what we have here, for ill.u.s.tration"s sake, supposed to be done with the watch, is exactly what the establishment of Darwin"s Theory will do for the organic world. For the notion that every organism has been created as it is and launched straight at a purpose, Mr.
Darwin subst.i.tutes the conception of something which may fairly be termed a method of trial and error. Organisms vary incessantly; of these variations the few meet with surrounding conditions which suit them and thrive; the many are unsuited and become extinguished.
According to Teleology, each organism is like a rifle bullet fired straight at a mark; according to Darwin, organisms are like grapeshot of which one hits something and the rest fall wide.
For the teleologist an organism exists because it was made for the conditions in which it is found; for the Darwinian an organism exists because, out of many of its kind, it is the only one which has been able to persist in the conditions in which it is found.
Teleology implies that the organs of every organism are perfect and cannot be improved; the Darwinian theory simply affirms that they work well enough to enable the organism to hold its own against such compet.i.tors as it has met with, but admits the possibility of indefinite improvement. But an example may bring into clearer light the profound opposition between the ordinary teleological, and the Darwinian, conception.
Cats catch mice, small birds and the like, very well. Teleology tells us that they do so because they were expressly constructed for so doing--that they are perfect mousing apparatuses, so perfect and so delicately adjusted that no one of their organs could be altered, without the change involving the alteration of all the rest. Darwinism affirms on the contrary, that there was no express construction concerned in the matter; but that among the mult.i.tudinous variations of the Feline stock, many of which died out from want of power to resist opposing influences, some, the cats, were better fitted to catch mice than others, whence they throve and persisted, in proportion to the advantage over their fellows thus offered to them.
Far from imagining that cats exist _in order_ to catch mice well, Darwinism supposes that cats exist because they catch mice well--mousing being not the end, but the condition, of their existence. And if the cat type has long persisted as we know it, the interpretation of the fact upon Darwinian principles would be, not that the cats have remained invariable, but that such varieties as have incessantly occurred have been, on the whole, less fitted to get on in the world than the existing stock.
If we apprehend the spirit of the "Origin of Species" rightly, then, nothing can be more entirely and absolutely opposed to Teleology, as it is commonly understood, than the Darwinian Theory. So far from being a "Teleologist in the fullest sense of the word," we should deny that he is a Teleologist in the ordinary sense at all; and we should say that, apart from his merits as a naturalist, he has rendered a most remarkable service to philosophical thought by enabling the student of Nature to recognise, to their fullest extent, those adaptations to purpose which are so striking in the organic world, and which Teleology has done good service in keeping before our minds, without being false to the fundamental principles of a scientific conception of the universe. The apparently diverging teachings of the Teleologist and of the Morphologist are reconciled by the Darwinian hypothesis.
But leaving our own impressions of the "Origin of Species," and turning to those pa.s.sages especially cited by Professor Kolliker, we cannot admit that they bear the interpretation he puts upon them. Darwin, if we read him rightly, does _not_ affirm that every detail in the structure of an animal has been created for its benefit. His words are (p. 199):--
"The foregoing remarks lead me to say a few words on the protest lately made by some naturalists against the utilitarian doctrine that every detail of structure has been produced for the good of its possessor. They believe that very many structures have been created for beauty in the eyes of man, or for mere variety. This doctrine, if true, would be absolutely fatal to my theory--yet I fully admit that many structures are of no direct use to their possessor."
And after sundry ill.u.s.trations and qualifications, he concludes (p. 200):--
"Hence every detail of structure in every living creature (making some little allowance for the direct action of physical conditions) may be viewed either as having been of special use to some ancestral form, or as being now of special use to the descendants of this form--either directly, or indirectly, through the complex laws of growth."
But it is one thing to say, Darwinically, that every detail observed in an animal"s structure is of use to it, or has been of use to its ancestors; and quite another to affirm, teleologically, that every detail of an animal"s structure has been created for its benefit. On the former hypothesis, for example, the teeth of the foetal _Baltaena_ have a meaning; on the latter, none. So far as we are aware, there is not a phrase in the "Origin of Species" inconsistent with Professor Kolliker"s position, that "varieties arise irrespectively of the notion of purpose, or of utility, according to general laws of Nature, and may be either useful, or hurtful, or indifferent."
On the contrary, Mr. Darwin writes (Summary of Chap. V.):--
"Our ignorance of the laws of variation is profound. Not in one case out of a hundred can we pretend to a.s.sign any reason why this or that part varies more or less from the same part in the parents... The external conditions of life, as climate and food, &c., seem to have induced some slight modifications. Habit, in producing const.i.tutional differences, and use, in strengthening, and disuse, in weakening and diminishing organs, seem to have been more potent in their effects."
And finally, as if to prevent all possible misconception, Mr. Darwin concludes his Chapter on Variation with these pregnant words:--
"Whatever the cause may be of each slight difference in the offspring from their parents--and a cause for each must exist--it is the steady acc.u.mulation, through natural selection of such differences, when beneficial to the individual, that gives rise to all the more important modifications of structure, by which the innumerable beings on the face of the earth are enabled to struggle with each other, and the best adapted to survive."
We have dwelt at length upon, this subject, because of its great general importance, and because we believe that Professor Kolliker"s criticisms on this head are based upon a misapprehension of Mr. Darwin"s views--substantially they appear to us to coincide with his own. The other objections which Professor Kolliker enumerates and discusses are the following: [Footnote: s.p.a.ce will not allow us to give Professor Kolliker"s arguments in detail; our readers will find a full and accurate version of them in the _Reader_ for August 13th and 20th, 1864.]--
"1. No transitional forms between existing species are known; and known varieties, whether selected or spontaneous, never go so far as to establish new species."
To this Professor Kolliker appears to attach some weight. He makes the suggestion that the short-faced tumbler pigeon may be a pathological product.
"2. No transitional forms of animals are met with among the organic remains of earlier epochs."
Upon this, Professor Kolliker remarks that the absence of transitional forms in the fossil world, though not necessarily fatal to Darwin"s views, weakens his case.
"3. The struggle for existence does not take place."
To this objection, urged by Pelzeln, Kolliker, very justly, attaches no weight.
"4. A tendency of organisms to give rise to useful varieties, and a natural selection, do not exist.
"The varieties which are found arise in consequence of manifold external influences, and it is not obvious why they all, or partially, should be particularly useful. Each animal suffices for its own ends, is perfect of its kind, and needs no further development. Should, however, a variety be useful and even maintain itself, there is no obvious reason why it should change any further. The whole conception of the imperfection of organisms and the necessity of their becoming perfected is plainly the weakest side of Darwin"s Theory, and a _pis aller_ (Nothbehelf) because Darwin could think of no other principle by which to explain the metamorphoses which, as I also believe, have occurred."
Here again we must venture to dissent completely from Professor Kolliker"s conception of Mr. Darwin"s hypothesis. It appears to us to be one of the many peculiar merits of that hypothesis that it involves no belief in a necessary and continual progress of organisms.
Again, Mr. Darwin, if we read him aright, a.s.sumes no special tendency of organisms to give rise to useful varieties, and knows nothing of needs of development, or necessity of perfection. What he says is, in substance: All organisms vary. It is in the highest degree improbable that any given variety should have exactly the same relations to surrounding conditions as the parent stock. In that case it is either better fitted (when the variation may be called useful), or worse fitted, to cope with them. If better, it will tend to supplant the parent stock; if worse, it will tend to be extinguished by the parent stock.
If (as is hardly conceivable) the new variety is so perfectly adapted to the conditions that no improvement upon it is possible,--it will persist, because, though it does not cease to vary, the varieties will be inferior to itself.
If, as is more probable, the new variety is by no means perfectly adapted to its conditions, but only fairly well adapted to them, it will persist, so long as none of the varieties which it throws off are better adapted than itself.
On the other hand, as soon as it varies in a useful way, _i.e._ when the variation is such as to adapt it more perfectly to its conditions, the fresh variety will tend to supplant the former.
So far from a gradual progress towards perfection forming any necessary part of the Darwinian creed, it appears to us that it is perfectly consistent with indefinite persistence in one state, or with a gradual retrogression. Suppose, for example, a return of the glacial epoch and a spread of polar climatal conditions over the whole globe. The operation of natural selection under these circ.u.mstances would tend, on the whole, to the weeding out of the higher organisms and the cherishing of the lower forms of life. Cryptogamic vegetation would have the advantage over Phanerogamic; _Hydrozoa_ over Corals; _Crustacea_ over _Insecta_, and _Amphipoda_ and _Isopoda_ over the higher _Crustacea;_ Cetaceans and Seals over the _Primates_; the civilisation of the Esquimaux over that of the European.
"5. Pelzeln has also objected that if the later organisms have proceeded from the earlier, the whole developmental series, from the simplest to the highest, could not now exist; in such a case the simpler organisms must have disappeared."
To this Professor Kolliker replies, with perfect justice, that the conclusion drawn by Pelzeln does not really follow from Darwin"s premises, and that, if we take the facts of Paleontology as they stand, they rather support than oppose Darwin"s theory.
"6. Great weight must be attached to the objection brought forward by Huxley, otherwise a warm supporter of Darwin"s hypothesis, that we know of no varieties which are sterile with one another, as is the rule among sharply distinguished animal forms.
"If Darwin is right, it must be demonstrated that forms may be produced by selection, which, like the present sharply distinguished animal forms, are infertile, when coupled with one another, and this has not been done."
The weight of this objection is obvious; but our ignorance of the conditions of fertility and sterility, the want of carefully conducted experiments extending over long series of years, and the strange anomalies presented by the results of the cross-fertilisation of many plants, should all, as Mr. Darwin has urged, be taken into account in considering it.
The seventh objection is that we have already discussed (_supra_ p.
82).
The eighth and last stands as follows:--
"8. The developmental theory of Darwin is not needed to enable us to understand the regular harmonious progress of the complete series of organic forms from the simpler to the more perfect.
"The existence of general laws of Nature explains this harmony, even if we a.s.sume that all beings have arisen separately and independent of one another. Darwin forgets that inorganic nature, in which there can be no thought of genetic connexion of forms, exhibits the same regular plan, the same harmony, as the organic world; and that, to cite only one example, there is as much a natural system of minerals as of plants and animals."