From the standpoint of the old psychology, a chapter bearing the above title would be considered quite out of place in a book on Thought-Culture, the Imagination being considered as outside the realm of practical psychology, and as belonging entirely to the idealistic phase of mental activities. The popular idea concerning the Imagination also is opposed to the "practical" side of its use. In the public mind the Imagination is regarded as something connected with idle dreaming and fanciful mental imaging. Imagination is considered as almost synonomous with "Fancy." But the New Psychology sees beyond this negative phase of the Imagination and recognizes the positive side which is essentially constructive when backed up with a determined will. It recognizes that while the Imagination is by its very nature _idealistic_, yet these ideals may be made real--these subjective pictures may be materialized objectively. The positive phase of the Imagination manifests in planning, designing, projecting, mapping out, and in general in erecting the mental framework which is afterward clothed with the material structure of actual accomplishment. And, accordingly, it has seemed to us that a chapter on "Constructive Imagination" might well conclude this book on Thought-Culture. Halleck says: "It was once thought that the imagination should be repressed, not cultivated, that it was in the human mind like weeds in a garden.... In this age there is no mental power that stands more in need of cultivation than the imagination. So practical are its results that a man without it cannot possibly be a good plumber. He must image short cuts for placing his pipe. The image of the direction to take to elude an obstacle must precede the actual laying of the pipe. If he fixes it before traversing the way with his imagination, he frequently gets into trouble and has to tear down his work. Some one has said that the more imagination a blacksmith has, the better will he shoe a horse. Every time he strikes the red-hot iron, he makes it approximate to the image in his mind. Nor is this image a literal copy of the horse's foot. If there is a depression in that, the imagination must build out a corresponding elevation in the image, and the blows must make the iron fit the image." Brodie says: "Physical investigation, more than anything else, helps to teach us the actual value and right use of the imagination--of that wondrous faculty, which, when left to ramble uncontrolled, leads us astray into a wilderness of perplexities and errors, a land of mists and shadows; but which, properly controlled by experience and reflection, becomes the noblest attribute of man, the source of poetic genius, the instrument of discovery in science, without the aid of which Newton would never have invented fluxions nor Davy have decomposed the earths and alkalies, nor would Columbus have found another continent."