The same state of affairs recurs wherever forms by themselves, dissociated from all practical uses and from all representation produce immediate effects upon the mind. In painting, in sculpture, in architecture and in poetry, we need equally to be on our guard against those who would attribute peculiar, unique and mystic virtues to forms in themselves. In every case their effect is due to the interplay (not the addition) of the effects which their elements excite. Especially we do well to beware of empty speculations upon ‘necessary and inevitable relations’ as the source of the effect. Of course in a given case a certain relation, a certain arrangement, may be necessary, in the sense that the elements if differently disposed would have a quite different combined effect. But this is not the sense in which necessity is usually claimed. It is necessity, in the metaphysical sense, some here utterly obscure kind of ‘logical necessity’ which is the favourite toy of a number of art critics. To those who have some familiarity both with Logic and with Psychology the regular appearance of the term ‘logical’ in describing these relations is the clearest indication that nothing definite or adequately considered is being said. The fact that, given certain elements arranged in a certain way, a certain further element can usually be introduced in one way and one way only _if a certain total effect is to be produced_, does, it is true, give a certain ‘inevitability’ to the artist’s work. But what the effect is and whether the effect is worth while have still to be considered, and this inevitability has nothing to do with _a priori_ rightness and is a matter simply of cause and effect. The salt required to make a soup palatable is ‘logically necessitated’ in this sense as much as any relation in a picture. The value lies not in the apprehension, conscious or subconscious, of the rightness of the relations, but in the total mental effect which, since they are right (i.e. since they work), they produce. [55] _The Power of Sound_, p. 176. CHAPTER XXI A Theory of Communication For surely once, they feel, we were Parts of a single continent. _Matthew Arnold._