This, too, is what I understand by an æsthetic sense of beauty; and if a hen bird has her sexual appetence evoked by the bright display of her mate, the emotional state she experiences is something very different from what we know as a sense of beauty. The adjective "æsthetic" should in any case, I think, be resolutely excluded in any discussion of sexual selection.

Æsthetics, like conceptual thought, accompany the suppression or postponement of action. As we have already seen, the normal and primitive series is (1) sense-stimulus; (2) certain nerve-processes in the brain which are associated with perception and emotion; and (3) certain resulting activities. By the suppression of action the mind comes to occupy itself more and more completely with the central processes. Perception blossoms forth into conceptual thought; emotion blossoms forth into æsthetics.

"'Throughout the whole range of sensations, perceptions, and emotions which we do not class as æsthetic,'[IJ] says Mr. Herbert Spencer, 'the states of consciousness serve simply as aids and stimuli to guidance and action. They are transitory, or, if they persist in consciousness some time, they do not monopolize the attention; that which monopolizes the attention is something ulterior, to the effecting of which they are instrumental. But in the states of mind we class as æsthetic the opposite attitude is maintained towards the sensations, perceptions, and emotions. These are no longer links in the chain of states which prompt and guide conduct. Instead of being allowed to disappear with merely passing recognition, they are kept in consciousness and dwelt upon, their natures being such that their continued presence in consciousness is agreeable.' The action which is the normal consequent on sensation is here postponed or suppressed; and thus we are enabled to make knowledge or beauty an end to be sought for its own sake; and thus, too, we are able to make progress, otherwise impossible, in science and in art. Sensations and perceptions are the roots from which spring the sturdy trunk of action, the expanded leaves of knowledge, and the fair blossoms of art. The leaves and the flowers are the terminal products along certain lines of development; but the function of the leaves is to minister to the growth of the wood, and the function of the flowers is to minister to the continuance and well-being of the race. So, too, in human affairs. Knowledge and art are justified by their influence on conduct; truth and beauty must ever guide us towards right living; and æsthetics are true or false according as they lead towards a higher or a lower standard of moral life."[IK]

To sum up, then, concerning this difficult subject, the following are the propositions on which I would lay stress: (1) What we term an æsthetic sense of beauty involves a number of complex perceptual, conceptual, and emotional elements. (2) The fact that a natural object excites in us this pleasurable emotion does not carry with it the implication that the object was evolved for the sake of its beauty. (3) Even if we grant, as we fairly may, that brightly coloured flowers, in association with nectar, have been objects of appetence to insects; and that brilliant plumage, in association with sexual vigour, has been a factor in the preferential mating of birds;—this is a very different thing from saying that, either in the selection of flowers by insects, or in the selection of their mates by birds, a consciously æsthetic motive has been a determining cause. (4) In fine, though animals may be incidentally attracted by beautiful objects, they have no æsthetic sense of beauty. A sense of beauty is an abstract emotion. Æsthetics involve ideals; and to ideals, if what has been urged in these pages be valid, no brute can aspire.

What applies thus to æsthetics applies also to ethics. Few, however, will be found to contend that animals can be moral or immoral, or have any moral ideas properly so called. Mr. Romanes does indeed state, in the table he prefixes to his works on Mental Evolution, that the anthropoid apes and dogs are capable of "indefinite morality." He leaves this to be explained, however, in a future work. In the published instalment of "Mental Evolution in Man" he seems to contend,[IL] or, at least, admit, "that the fundamental concepts of morality are of later origin than the names by which they have been baptized." But he says nothing of indefinite morality, which still remains for consideration in another work. In the mean while we may, I think, confidently assume that ethics, like conceptual thought and æsthetics, are beyond the reach of the brute. Morality is essentially a matter of ideals, and these belong to the conceptual sphere.

I have now said enough[IM] to indicate what I mean by advocating the exercise of extreme caution in our inferences concerning the emotional states of animals. We must remember, first, how liable to error are our inferences in these matters; we must remember, next, how complex and essentially human are our own emotions. I do not for one moment deny that in animals are to be found the perceptual germs of even the higher emotional states. Nevertheless, if we employ, in our interpretation of the actions of animals, such terms as "consciousness of guilt," "sense of right and wrong," "idea of justice," "deceitfulness," "revenge," "vindictiveness," "shame," and the rest, we must not forget that these terms stand for human products, that they are saturated with conceptual thought, and that they must be to a large extent emptied of their meaning before they can become applicable to the emotional consciousness of brutes.