Third Period. It is definite: in some way or another and in some degree the imagination has become rationalized, but this change is not reducible to a single formula.
(1) The creative imagination falls, as is indicated in the figure, where the imagination curve MN´ descends rapidly toward the line of abcissas without ever reaching it. This is the most general case; only truly imaginative minds are exceptions. One falls little by little into the prose of practical life—such is the downfall of love which is treated as a phantom, the burial of the dreams of youth, etc. This is a regression, not an end; for the creative imagination disappears completely in no man; it only becomes accessory.
(2) It keeps up but becomes transformed; it adapts itself to the conditions of rational thought; it is no longer pure imagination, but becomes a mixed form—the fact is indicated in the diagram by the union of the two lines, MN, the imagination, and XO, the rational. This is the case with truly imaginative beings, in whom inventive power long remains young and fresh.
This period of preservation, of definitive constitution with rational transformation, presents several varieties. First, and simplest, transformation into logical form. The creative power manifested in the first stage remains true to itself, and always follows the same trend. Such are the precocious inventors, those whose vocation appeared early and never changed direction. Invention loses its childish or juvenile character in becoming virile; there are no other changes. Compare Schiller's Robbers, written in his teens, with his Wallenstein, dating from his fortieth year; or the vague sketches of the adolescent James Watt with his inventions as a man.
Another case is the metamorphosis or deviation of creative power. We know what numbers of men who have left a great name in science, politics, mechanical or industrial invention started out with mediocre efforts in music, painting, and especially poetry, the drama, and fiction. The imaginative impulse did not discover its true direction at the outset; it imitated while trying to invent. What has been said above concerning the chronological development of the imagination would be tiresome repetition. The need of creating followed from the first the line of least resistance, where it found certain materials ready to hand. But in order to arrive to full consciousness of itself it needed more time, more knowledge, more accumulated experience.
We might here ask whether the contrary case is also met with; i.e., where the imagination, in this third period, would return to the inclinations of the first period. This regressive metamorphosis—for I cannot style it otherwise—is rare but not without examples. Ordinarily the creative imagination, when it has passed its adult stage, becomes attenuated by slow atrophy without undergoing serious change of form. Nevertheless, I am able to cite the case of a well-known scholar who began with a taste for art, especially plastic art, went over rapidly to literature, devoted his life to biologic studies, in which he gained a very deserved reputation; then, in turn, became totally disgusted with scientific research, came back to literature and finally to the arts, which have entirely monopolized him.
Finally—for there are very many forms—in some the imagination, though strong, scarcely passes beyond the first stage, always retains its youthful, almost childish form, hardly modified by a minimum of rationality. Let us note that it is not a question here of the characteristic ingenuousness of some inventors, which has caused them to be called "grown-up children," but of the candor and inherent simplicity of the imagination itself. This exceptional form is hardly reconcilable except with esthetic creation. Let us add the mystic imagination. It could furnish examples, less in its religious conceptions, which are without control, than in its reveries of a scientific turn. Contemporary mystics have invented adaptations of the world that take us back to the mythology of early times. This prolonged childhood of the imagination, which is, in a word, an anomaly, produces curiosities rather than lasting works.
At this third period in the development of the imagination appears a second, subsidiary law, that of increasing complexity; it follows a progressive line from the simple to the complex. Indeed, it is not, strictly speaking, a law of the imagination but of the rational development exerting an influence on it by a counter-action. It is a law of the mind that knows, not of one that imagines.
It is needless to show that theoretical and practical intelligence develops as an increasing complex. But from the time that the mind distinguishes clearly between the possible and the impossible, between the fancied and the real—which is a capacity wanting in primitive man—as soon as man has formed rational habits and has undergone experience the impress of which is ineffaceable, the creative imagination is subject, nolens volens, to new conditions; it is no longer absolute mistress of itself, it has lost the assurance of its infancy, and is under the rules of logical thought, which draws it along in its train. Aside from the exceptions given above—and even they are partial exceptions only—creative power depends on the ability to understand, which imposes upon it its form and developmental law. In literature and in the arts comparison between the simplicity of primitive creations and the complexity of advanced civilizations has become commonplace. In the practical, technical, scientific and social worlds the higher up we go the more we have to know in order to create, and in default of this condition we merely repeat when we think we are inventing.