With such a general sensibility, Darwin’s attitude towards vivisection is extremely curious. Knowing as he did the importance of animal experiment, he could not possibly range himself on the side of the anti-vivisectionists. But he supported every effort to have humanity legally emphasized and rigidly insisted upon. The nature of his feeling in the matter appears clearly in a passage of ‘The Descent of Man’: ‘Every one has heard of the dog suffering under vivisection, who licked the hand of the operator; this man, unless the operation was fully justified by an increase of our knowledge, or unless he had a heart of stone, must have felt remorse to the last hour of his life.’[326] In sociological questions of a broader bearing, which made no such immediate appeal to his susceptibilities, Darwin took much less interest. Now and then some special point arouses him. He was excited about any attempt to interfere with the marriage of cousins, because he had married his cousin and had in consequence largely investigated the subject.[327] He was decidedly opposed to the English tradition of primogeniture, and felt its unfairness. On the land-question he writes to Wallace: ‘I see you are going to write on the most difficult political question, the land. Something ought to be done; but what, is the rub.’[328] In the same spirit of remoteness and uncertainty, he writes also to Wallace in regard to Henry George’s ‘Progress and Poverty’: ‘I will certainly order “Progress and Poverty,” for the subject is a most interesting one. But I read many years ago some books on political economy, and they produced a disastrous effect on my mind, viz., utterly to distrust my own judgment on the subject, and to doubt much every one else’s judgment. So =I feel= sure that Mr. George’s book will only make my mind worse confounded than it is at present.’[329] But it is clear that the remoteness did not imply contempt or cynical disregard, merely a feeling of complete inability and diffidence in regard to economic problems, and one is slow to condemn this state of mind, when one thinks that such problems are usually dealt with and solved, if it can be called so, by those in whose equipment freedom from diffidence is the most aggressive and impressive instrument. II With artistic and general æsthetic matters, Darwin, at any rate in later years, was even more indifferent than with political. It is true that his scientific investigations sometimes involved the abstract analysis of æsthetics: ‘I agree with what you say about beauty. I formerly thought a good deal on the subject, and was led quite to repudiate the doctrine of beauty being created for beauty’s sake.’[330] The theory of sexual selection, as presented in ‘The Descent of Man,’ necessitated a good deal of discussion of the susceptibility to color and form and to music. But such æsthetic discussion has nothing whatever to do with æsthetic enjoyment.