In this phrase we see why imagination ranks as a criterion of mental development. Ruled chiefly by unconscious instinct the brute has no other aims than to feed and sleep and reproduce his kind; men of low degree add to these, perhaps, the lust of power or of gold or of amusement, or other such vain and paltry ambitions; but the soul that seeks the highest has aims beyond all fulfilment, but which by their glory stimulate its activities to the utmost and lift it into a life above all mundane satisfactions. _The Ideal._—By the plastic power of the active imagination is formed the Ideal, the most potent of all the stimulants of the higher culture. Based on reality and experience, it transcends the possibilities of both, and lifts the soul into realms whose light is not on sea or land, and whose activities aim at results beyond any present power of human nature to achieve. But it is only by striving for that which is beyond reach that the utmost effort possible can be called forth. The ideal, some ideal, is present in every human heart. It is the goal toward which each strives in seeking pleasure and in avoiding pain. Through the unity of the human mind, the same ideals, few in number, have directed the energies of men in all times and climes. Around them have concentrated the labours of nations, and as one or the other became more prominent, national character partook of its inspiration, and national history fell under its sway. Constantly in the history of culture do we see such general devotion to an ideal lead groups toward or away from the avenue to progress and vitality. _Consciousness and Self-Consciousness._—Through ideation arises man’s consciousness of himself as an independent personality. In its broadest sense, that of reaction to an external stimulus, consciousness is a property of all animals, perhaps of all organic tissues. Contractility and motility depend upon it. What it is, “in itself,” we have no means of knowing; therefore it is safe to agree with Professor Cope in his negative opinion that it “is qualitatively comparable to nothing else.” In simpler forms of organic life it must be merely rudimentary; but in most animals it reaches what has been called the “projective” stage; that is, the animal is conscious of the existence of others, like or unlike himself, though he is not yet conscious of himself as a separate entity. This has been held to explain, psychologically, the “gregarious instincts” of many lower species. As a result of the absence of general concepts, the brute does not contemplate himself as a single individual in contrast to the others of his species. He is unable to class these under a general term or thought. Hence _self_-consciousness belongs to man alone.