Any association of ideas may be called imaginary if it occurs in an order different from the order of experience. But the term Imagination is properly confined to novel combinations deliberately and consciously formed to serve some utility. It is thus distinguished from Reverie, in which no choice or control enters into the recollection. We control our ideal associations by means of comparison, which is therefore what distinguishes imagination from reverie. For instance, if I see a vase from which the handle has been broken off, I can imagine the handle restored, but to do this I must be able to compare the broken vase with a similar whole vase, or with the general idea 'whole vase.' The combination I form is novel, for I have never seen this particular vase in a whole state; if I had I should not be imagining it but recollecting it. There are two principal distinctions to be noticed in imagination; one relates to the mode of forming the imaginary idea, the other to its use. In the above case we form the whole by mechanical extension or addition. The process is as simple as nailing one piece of wood to another. But suppose the broken vase is of porcelain and the whole one of bronze, the restoration can still be made, but it is no mechanical junction of two previous ideas. It is a fusion of the material supplied by one idea with a form supplied by another. On the same principle a vase may be wholly designed from hints supplied by a score or more of vases, differing in material, in size, colour, decoration, and so forth. In these cases the new idea may be said to be totally different throughout its length from any other and from any object. Yet it is a combination of previous ideas. We do not create any absolutely new idea. This may be called imagination by _transfusion_. The elements may be so well mixed that it is impossible to trace each back to its origin. Transfusion may be further complicated by recompounding ideas already compound. This occurs, as we shall see, in forming the 'external world' of materialists and realists. The two uses to which imaginary ideas are put are the Artistic and the Rational. We have seen (X) that emotions may be excited by objects or ideas. Hence, agreeable emotions may be excited by suggesting the objects associated with the original agreeable feelings; and novel emotions may be excited by novel combinations of the ideas of experienced objects that have been signs of feelings. From this possibility has arisen that extensive province of activity called ART, which consists in imagining novel combinations of things capable of exciting novel and pleasurable emotions (not feelings), and in finding means of suggesting such ideas to others. Some of these combinations are so subtle, and the emotions they excite so exquisite, that we value the artistic work at a great price, and rank the man who imagined it among the benefactors of his species.