Halleck says: "* * * We must not forget that any one not shallow and fickle can soon discover something interesting in most objects * * * the attention which they are able to give generally ends in finding a pearl in the most uninteresting looking oyster. * * * The essence of genius is to present an old thing in new ways." And again: "When we think about a thing, or keep the mind full of a subject, the activity in certain brain tracts is probably much increased. As a result of this unconscious preparation, a full fledged image may suddenly arise in consciousness." Hoffding says: "The inter-weaving of the elements of the picture in the imagination takes place in great measure below the threshold of consciousness, so that the image suddenly emerges in consciousness complete in its broad outlines, the conscious result of an unconscious process." Halleck also says: "A representative image of the thing desired is the necessary antecedent to desire. Not until a representative idea comes to the mind does desire arise. It has often been said that where there is no knowledge there can be no desire. A child sees a new toy and wants it. A man notices some improvements about his neighbor's house and wishes them. One nation finds out that another has a war ship of a superior model, and straightway desires something as good or better. A scholar sees a new cyclopedia or work of reference, and desire for it arises. A person returns and tells his friends how delightful a foreign trip is. Their desires for travel increase. Knowledge gives birth to desire, and desire points out the point to will." In this paragraph we have quoted eminent authorities, showing the direct line of psychological progress from interested investigation, through imagination, to desire and will. One investigates and gains favorable knowledge regarding a subject; then his imagination operates to show him the possibility of its successful application to his personal case; then his desire for the thing is awakened.