Productive imagery may be classified as fanciful, realistic, and idealistic according to the character of the material used. Fanciful productive imagery is characterized by its spontaneity, its disregard of the probable and possible, its vividness of detail. It is its own reward, and does not look to any result beyond itself. Little children's imaginations are of this type--it is their play world of make-believe. The incongruity and absurdity of their images have been compared to the dreams of adults. Lacking in experience, without knowledge of natural laws, their imagination runs riot with the materials it has at its command. Some adults still retain it to a high degree--witness the myths and fairy stories, "Alice in Wonderland," and the like. All adults in their "castle-building" indulge in this type of imagery to some extent. Realistic productive imagery, as its name implies, adheres more strictly to actual conditions, it deals with the probable. It usually is constructed for a purpose, being put to some end beyond itself. It lacks much of the emotional element possessed by the other two types. This is the kind most valuable in reasoning and thinking. It deals with new situations--constructs them, creates means of dealing with them, and forecasts the results. It is the type of productive imagery called into play by inventors, by craftsmen, by physicians, by teachers--in fact, by any one who tries to bring about a change in conditions by the functioning of a definite thought process. This is the kind of imagery which most interests grammar school pupils. They demand facts, not fancies. They are most active in making changes in a world of things. Idealistic productive imagery does not fly in the face of reality as does the fanciful, nor does it adhere so strictly to facts as does the realistic. It deals with the possible--with what may be, but with what is not yet. It always looks to the future, for if realized it is no longer idealistic. It is enjoyed for its own sake but does not exist for that alone, but looks towards some result. It is concerned primarily with human lives and has a strong emotional tone. It is the heart of ideals. The adolescent revels in this type of productive imagery. His dreams concerning his own future, his service to his fellow men, his success, and the like involve much idealistic imagery. Hero worship involves it. It is one of the differences between the man with "vision" and the man without.