may in a positive manner fix the
value of the phenomenon in invention, all the more as we are inclined to
over-value it. We should, indeed, note that inspiration is not a cause
but an effect--more exactly, a moment, a crisis, a critical stage; it is
an _index_. It marks either the end of an unconscious elaboration which
may have been very short or very long, or else the beginning of a
conscious elaboration which will be very short or very long (this is
seen especially in cases of creation suggested by chance). On the one
hand, it never has an absolute beginning; on the other hand, it never
delivers a finished work; the history of inventions sufficiently proves
this. Furthermore, one may pass beyond it; many creations long in
preparation seem without a crisis, strictly so called; such as Newton's
law of attraction, Leonardo da Vinci's "Last Supper," and the "Mona
Lisa." Finally, many have felt themselves really inspired without
producing anything of value.[22]

II

What has been said up to this point does not exhaust the study of the
unconscious factor as a source of new combinations. Its role can be
studied under a simpler and more limited form. For this purpose we need
to return for the last time to association of ideas. The final reason
for association (outside of contiguity, in part at least) must be sought
in the temperament, character, individuality of the subject, often even
in the _moment_; that is, in a passing influence, hardly perceptible
because it is unconscious or subconscious. These momentary dispositions
in latent form can excite novel relations in two ways--through mediate
association and through a special mode of grouping which has recently
received the name "constellation."

1. Mediate association has been well known since the time of Hamilton,
who was the first to determine its nature and to give a personal example
that has become classic. Loch Lomond recalled to him the Prussian system
of education because, when visiting the lake, he had met a Prussian
officer who conversed with him on the subject. His general formula is
this: _A_ recalls _C_, although there is between them neither contiguity
nor resemblance, but because a middle term, _B_, which does not enter
consciousness, serves as a transition between _A_ and _C_. This mode of
association seemed universally accepted when, latterly, it has been
attacked by Muensterberg and others. People have had recourse to
experimentation, which has given