The general function which desire subserves in stimulating advantageous action is obvious. As anger and fear are primarily useful emotions in view of potential pain and harm, so desire in view of potential pleasure and benefit. The function of desire in stimulating advantageous action is obvious. Desire answers to potential pleasure and benefit just as anger does to potential pain and harm. It is a correlative and supplement of fear, and in general the more one fears a thing the more one desires the opposite. When sailing I desire fair weather in proportion as I fear a squall. Desire is the very spring of life and progress, and when desire is extinguished the will to live ceases, and psychic life declines and dies. Fulness of desire is fulness of life, and the largest mental life is that in which desire, constant, multiplex, and far-reaching, is strong and dominant. Desire seems thus to be a permanent factor, and, though there is a pre-desire period, no post-desire age seems to be indicated in psychic history so far. Somewhat as to the analysis of desire has already been intimated in touching upon its origin and function, but we are now to study its elements more in detail. The very young infant certainly experiences hunger pains in almost its initial consciousness; but it is only gradually that the need felt leads up to presentation and representation of the needed thing, and so to desire. Hunger with it, as with all organisms, sharpens the wits, and leads to knowing things, interpreting them, and acting definitely toward them. Through touch it first comes to appreciate object, and object as food, a representative–inductive act. The earliest meaning attached to object is edibility, and this, indeed, indiscriminately to all objects, as we see that infants mouth everything. Gradually from this, or by dint of a good deal of unpleasant experience, objects are divided into edible and non-edible, the primitive classification of things.