(2) The others, more numerous, are easy to explain. They are physiological means consciously or unconsciously chosen to aid creative work; they are auxiliary helpers of the imagination.
The most frequent method consists of artificially increasing the flow of blood to the brain. Rousseau would think bare-headed in full sunshine; Bossuet would work in a cold room with his head wrapped in furs; others would immerse their feet in ice-cold water (Grétry, Schiller). Very numerous are those who think "horizontally"—that is, lying stretched out and often flattened under their blankets (Milton, Descartes, Leibniz, Rossini, etc.)
Some require motor excitation; they work only when walking,[26] or else prepare for work by physical exercise (Mozart). For variety's sake, let us note those who must have the noise of the streets, crowds, talk, festivities, in order to invent. For others there must be external pomp and a personal part in the scene (Machiavelli, Buffon). Guido Reni would paint only when dressed in magnificent style, his pupils crowded about him and attending to his wants in respectful silence.
On the opposite side are those requiring retirement, silence, contemplation, even shadowy darkness, like Lamennais. In this class we find especially scientists and thinkers—Tycho-Brahé, who for twenty-one years scarcely left his observatory; Leibniz, who could remain for three days almost motionless in an armchair.
But most methods are too artificial or too strong not to become quickly noxious. Every one knows what they are—abuse of wine, alcoholic liquors, narcotics, tobacco, coffee, etc., prolonged periods of wakefulness, less for increasing the time for work than to cause a state of hyperesthesia and a morbid sensibility (Goncourt).
Summing up: The organic bases of the creative imagination, if there are any specially its own, remain to be determined. For in all that has been said we have been concerned only with some conditions of the general working of the mind—assimilation as well as invention. The eccentricities of inventors studied carefully and in a detailed manner would finally, perhaps, be most instructive material, because it would allow us to penetrate into their inmost individuality. Thus, the physiology of the imagination quickly becomes pathology. I shall not dwell on this, having purposely eliminated the morbid side of our subject. It will, however, be necessary to return thereto, touching upon it in another part of this essay.
III
There remains a problem, so obscure and enigmatic that I scarcely venture to approach it, in the analogy that most languages—the spontaneous expression of a common thought—establish between physiologic and psychic creation. Is it only a superficial likeness, a hasty judgment, a metaphor, or does it rest on some positive basis? Generally, the various manifestations of mental activity have as their precursor an unconscious form from which they arise. The sensitiveness belonging to living substance, known by the names heliotropism, chemotropism, etc., is like a sketch of sensation and of the reactions following it; organic memory is the basis and the obliterated form of conscious memory. Reflexes introduce voluntary activity; appetitions and hidden tendencies are the forerunners of effective psychology. Instinct, on several sides, is like an unconscious and specific trial of reason. Has the creative power of the human mind also analogous antecedents, a physiological equivalent?
One metaphysician, Froschammer, who has elevated the creative imagination to the rank of primary world-principle, asserts this positively. For him there is an objective or cosmic imagination working in nature, producing the innumerable varieties of vegetable and animal forms; transformed into subjective imagination it becomes in the human brain the source of a new form of creation. "The very same principle causes the living forms to appear—a sort of objective image—and the subjective images, a kind of living form."[27] However ingenious and attractive this philosophical theory may be, it is evidently of no positive value for psychology.
Let us stick to experience. Physiology teaches that generation is a "prolonged nutrition," a surplus, as we see so plainly in the lower forms of agamous generation (budding, division). The creative imagination likewise presupposes a superabundance of psychic life that might otherwise spend itself in another way. Generation in the physical order is a spontaneous, natural tendency, although it may be stimulated, successfully or otherwise, by artificial means. We can say as much of the other. This list of resemblances it would be easy to prolong. But all this is insufficient for the establishment of a thorough identity between the two cases and the solution of the question.