r general
and special sensibility; the modes of their memory and forms of
association, their intellectual processes, etc. But up to this time no
conclusion has been drawn from these individual descriptions that would
allow any generalization. Besides, has an experiment, in the strict
sense of the word, ever been made at the "psychological moment"? I know
of none. Would it be possible? Let us admit that by some happy chance
the experimenter, using all his means of investigation, can have the
subject under his hand at the exact moment of inspiration--of the
sudden, fertile, brief creative impulse--would not the experiment itself
be a disturbing cause, so that the result would be _ipso facto_
vitiated, or at least unconvincing?

There still remains a mass of facts deserving summary notice--the
oddities of inventors. Were we to collect only those that may be
regarded as authentic we could make a thick volume. Despite their
anecdotal character these evidences do not seem to be unworthy of some
regard.

It is impossible to enter here upon an enumeration that would be
endless. After having collected for my own information a large number of
these strange peculiarities, it seems to me that they are reducible to
two categories:

(1) Those inexplicable freaks dependent on the individual constitution,
and more often probably also on experiences in life the memory of which
has been lost. Schiller, for example, kept rotten apples in his work
desk.

(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 (Gretry, 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 o