Some who hold firmly to the æsthetic character of certain groups of impressions (for example, the visual and auditive), and exclude others, are nevertheless ready to admit that if visual and auditive impressions enter _directly_ into the æsthetic fact, those of the other senses also enter into it, but only as _associated._ But this distinction is altogether arbitrary. Æsthetic expression is synthesis, in which it is impossible to distinguish direct and indirect. All impressions are placed by it on a level, in so far as they are æstheticized. A man who absorbs the subject of a picture or poem does not have it before him as a series of impressions, some of which have prerogatives and precedence over the others. He knows nothing as to what has happened prior to having absorbed it, just as, on the other hand, distinctions made after reflexion have nothing whatever to do with art as such.
The theory of the æsthetic senses has also been presented in another way; as an attempt to establish what physiological organs are necessary for the æsthetic fact. The physiological organ or apparatus is nothing but a group of cells, constituted and disposed in a particular manner; that is to say, it is a merely physical and natural fact or concept. But expression does not know physiological facts. Expression has its point of departure in the impressions, and the physiological path by which these have found their way to the mind is to it altogether indifferent. One way or another comes to the same thing: it suffices that they should be impressions.
It is true that the want of given organs, that is, of certain groups of cells, prevents the formation of certain impressions (when these are not otherwise obtained through a kind of organic compensation). The man born blind cannot intuite and express light. But the impressions are not conditioned solely by the organ, but also by the stimuli which operate upon the organ. One who has never had the impression of the sea will never be able to express it, in the same way as one who has never had the impression of the life of high society or of the political arena will never express either. This, however, does not prove the dependence of the expressive function on the stimulus or on the organ. It merely repeats what we know already: expression presupposes impression, and particular expressions particular impressions. For the rest, every impression excludes other impressions during the moment in which it dominates; and so does every expression.