But nothing more is contributed to this theory either by the doctrine of Darwin or by that of Lamarck. So it follows that almost everything has still to be done; for no hypothesis at present accounts for the foundation of all systematics, viz., for the differences in organisation, in all that relates to the so-called types as such and the degree of complication in these types, both of which (types and degree of complication) are independent of histological adaptation and adaptedness.
What then do we know about any facts that might be said to bear on this problem? We have stated already at the end of our chapter devoted to the analysis of heredity that what we actually know about any deviation of inheritance proper, that is, about congenital differences between the parents and the offspring, relating to mere tectonics, is practically nothing: indeed, there are at our disposal only the few facts observed by de Vries or derived from the experience of horticulturalists and breeders. We may admit that these facts at least prove the possibility[159] of a discontinuous variation, that is of “mutation,” following certain lines of tectonics and leading to constant results; but everything else, that is everything about a real theory of phylogeny, must be left to the taste of each author who writes on the theory of the Living. You may call that a very unscientific state of affairs, but no other is possible.
And, in fact, it has been admitted by almost all who have dealt with transformism without prepossessions that such is the state of affairs. Lamarck himself, as we have mentioned already, was not blind to the fact that a sort of organisatory law must be at the base of all transformism, and it is well known that hypothetical statements about an original law of phylogeny have been attempted by Nägeli, Kölliker, Wigand, Eimer, and many others. But a full discussion of all these “laws” would hardly help us much in our theoretical endeavour, as all of them, it must be confessed, do little more than state the mere fact that some unknown principle of organisation must have been at work in phylogeny, if we are to accept the theory of descent at all.
It is important to notice that even such a convinced Darwinian as Wallace, who is well known to have been an independent discoverer of the elimination principle, admitted an exception to this principle in at least one case—with regard to the origin of man. But one exception of course destroys the generality of a principle.
As we ourselves feel absolutely incapable of adding anything specific to the general statement that there must be an unknown principle of transformism, if the hypothesis of descent is justified at all, we may here close our discussion of the subject.
5. The Logical Value of the Organic Form According to the
Different Transformistic Theories
A few words only must be added about two topics: on the character of organic forms as regarded by the different transformistic theories, and on the relation of transformism in general to our concept of entelechy.
We have learnt that both Darwinism and Lamarckism, in their dogmatic shape, regard the specific forms of animals and plants as being contingent; in fact, it was to this contingency that criticism was mainly directed. We therefore are entitled to say that to Darwinism and Lamarckism organic forms are accidental in the very sense of the forma accidentalis of the old logicians. There are indefinite forms possible, according to these theories, and there is no law relating to these forms. Systematics, under such a view, must lose, of course, any really fundamental importance. “There is no rational system about organisms”: that is the ultimate statement of Darwinism and of Lamarckism on this doubtful question. Systematics is a mere catalogue, not at present only, but for ever, by the very nature of the organisms. It is not owing to the indefinite number of possible forms that both our theories came to deny the importance of systematics, but to the want of a law relating to this indefinite number: among chemical compounds indefinite possibilities also exist in some cases, but they obey the law of the general formula. It is very strange that Darwinians of all people are in the forefront of systematic research in all countries: do they not see that what they are trying to build up can only relate to accidental phenomena? Or have they some doubts about the foundations of their own theoretical views, in spite of the dogmatic air with which they defend them? Or is it the so-called historical interest which attracts them?
A new question seems to arise at this point: Have not we ourselves neglected history in favour of systematics and laws? Our next lecture, the last of this year, will give the answer to this question.