e adopt--the
whole of which constitutes the instinct of individual preservation, have
been the generators of all inventions dealing with food-getting,
housing, making of weapons, instruments, and machines.

The need for individual and social expansion or extension has given rise
to military, commercial, and industrial invention, and in its
disinterested form, esthetic creation.

As for the sexual instinct, its psychic fertility is in no way less than
the physical--it is an inexhaustible source of imagination in everyday
life as well as in art.

The wants of man in contact with his fellows have engendered, through
instinctive or reflective action, the numerous social and practical
creations regulating human groups, and they are rough or complex, stable
or unstable, just or unjust, kindly or harsh.

The need of knowing and of explaining, well or ill, has created myths,
religions, philosophical systems, scientific hypotheses.

Every want, tendency or desire may, then, become creative, by itself or
associated with others, and into these final elements it is that
analysis must resolve "creative spontaneity." This vague expression
corresponds to a _sum_, not to a special property.[147] Every invention,
then, has a _motor_ origin; _the ultimate basis of the constructive
imagination is motor_.

2. But needs and desires by themselves cannot create--they are only a
stimulus and a spring. Whence arises the need of a second condition--the
spontaneous revival of images.

In many animals that are endowed only with memory the return of images
is always provoked. Sensation from without or from within bring them
into consciousness under the form, pure and simple, of former
experience; whence we have reproduction, repetition without new
associations. People of slight imagination and used to routine approach
this mental condition. But, as a matter of fact, man from his second
year on, and some higher animals, go beyond this stage--they are capable
of spontaneous revival. By this term I mean that revival that comes
about abruptly, without _apparent_ antecedents. We know that these act
in a latent form, and consist of thinking by analogy, affective
dispositions, unconscious elaboration. This sudden appearance excites
other states which, grouped into new associations, contain the first
elements of the creative act.

Taken altogether, and however numerous its manifestations, the
constructive imagination seems to me reducible to thre