versities in creation, however numerous, should be
reducible to types that are _varieties_ of imagination, and the
determination of these varieties is analogous to that of character as
related to will. Indeed, when we have settled upon the physiological and
psychological conditions of voluntary activity we have only done a work
in _general_ psychology. Men being variously constituted, their modes of
action bear the stamp of their individuality; in each one there is a
personal factor that, whatever its ultimate nature, puts its mark on the
will and makes it energetic or weak, rapid or slow, stable or unstable,
continuous or intermittent. The same is true of the creative
imagination. We cannot know it completely without a study of its
varieties, without a special psychology, toward which the following
chapters are an attempt.

How are we to determine these varieties? Many will be inclined to think
that the method is indicated in advance. Have not psychologists
distinguished, according as one or another of image-groups
preponderates, visual, auditory, motor and mixed types? Is not the way
clear and is it not well enough to go in this direction? However natural
this solution may appear, it is illusory and can lead to naught. It
rests on the equivocal use of the word "imagination," which at one time
means mere reproduction of images, and at another time creative
activity, and which, consequently, keeps up the erroneous notion that in
the creative imagination images, the raw materials, are the essential
part. The materials, no doubt, are not a negligible element, but by
themselves they cannot reveal to us the species and varieties that have
their origin in an anterior and superior tendency of mind. We shall see
in the sequel that the very nature of constructive imagination may
express itself indifferently in sounds, words, colors, lines, and even
numbers. The method that should allege to settle the various
orientations of creative activity according to the nature of images
would no more go to the bottom of the matter than would a classification
of architecture according to the materials employed (as rock, brick,
iron, wood, etc.) with no regard for differences of style.

This method aside, since the determination must be made according to the
individuality of the architect, what method shall we follow? The matter
is even more perplexing than the study of character. Although various
authors have treated the latter subject (we