An idea, then, becomes or _is made into_ an idea of imagination by its mental setting, which is this feeling of strangeness, the opposite of the feeling of familiarity. As regards the nature of the feeling, we may guess that it is _the modern representative of primitive man’s anxiety and uneasiness in face of the unknown_, an echo from the time when the new was the dangerous (p. 179). If the idea is often repeated, the feeling wears off, and is replaced by a directive brain-habit; we still take it _as_ an idea of imagination, but we do not re-imagine it. If it is still further repeated, it ceases even to be taken as imaginative, and becomes one of the habitual images that we spoke of on p. 77. There is a second difference between _the idea of imagination_ and the idea of memory: the difference, namely, that the former _cannot be replaced by another mode of imagery_. An idea of imagination must not simply mean something new; it must _be_ something new. We know that images of imagination are not indispensable to artistic work; painters do not necessarily possess visual imagery (p. 141). Where the idea of imagination does exist, however, it keeps its original form. The French mural painter Puvis de Chavannes used to contemplate, for days together, the bare spaces that he was to fill; ‘wasting time,’ a friend told him, and received the reply “I have to see my picture before I can paint it.” In a case like this, the mental picture—though it may be modified as the actual colours are laid on, or as new outlines suggest themselves to the painter—must, so far as it furnishes a guide and model, hold its form and colour-scheme almost as fixedly as a perception; otherwise it would be useless. So a man may be a very good musician, and possess no auditory images. Yet Beethoven composed his Ninth Symphony in 1823, when he had long been deaf; and he could not even have helped his mental ear by the kinæsthesis of singing, since without special education the deaf soon lose control of the larynx. In his case, therefore, the auditory imagination must not only have held good, but must also have grown more complex and more keenly discriminative, up to the very end. No doubt, he was aided by the eye; the symphony grew on paper, a theme at a time; and, no doubt also, he used his general knowledge of what would sound aright and what would not; he was a practised composer. But, when all allowance is made, his main reliance must have been on auditory imagery, and this must have remained as stable as auditory perception. Such instances prove that _the idea of imagination runs a different course from the idea of memory_. The memory-idea is common to all minds; it persists as meaning, under the limitations of imaginal type and the general laws of associative tendency. _The idea of imagination seems to depend rather upon special endowment_; it persists in kind, also under the limitations of imaginal type; and it is conserved by some special