External conditions:--Geographical, political, economic, social,
etc., varying according to time, place, and people. Such is its external
determinism--human and social here in place of cosmic, physical, as in
mechanical invention.

(2) Internal, psychological conditions, most of which are foreign to the
primary and essential inventive act:--on one hand, foresight,
calculation, strength of reasoning;--in a word, capacity for reflection;
on the other hand, assurance, recklessness, soaring into the unknown--in
a word, strong capacity for action. Whence arise, if we leave out the
mixed forms, two principal types--the calculating, the venturesome. In
the former the rational element is first. They are cautious,
calculating, selfish exploiters, with no great moral or social
preoccupations. In the latter, the active and emotional element
predominates. They have a broader sweep. Of this sort were the
merchant-sailors of Tyre, Carthage, and Greece; the merchant-travelers
of the Middle Ages, the mercantile and gain-hungry explorers of the
fifteenth, sixteenth, and seventeenth centuries; later, in a changed
form, the organizers of great companies, the inventors of monopolies,
American "trusts," etc. These are the great imaginative minds.

Eliminating, then, from our subject, what is not the purely imaginative
element in order to study it alone, I see only two points for us to
treat, if we would avoid repetition--at the initial moment of invention,
the intuitive act that is its germ; during the period of development and
organization, the necessary and exclusive role of schematic images.

I

By "intuition" we generally understand a practical, immediate judgment
that goes straight to the goal. Tact, wisdom, scent, divination, are
synonymous or equivalent expressions. First let us note that intuition
does not belong exclusively to this part of our subject, for it is found
_in parvo_ throughout; but in commercial invention it is preponderating
on account of the necessity of perceiving quickly and surely, and of
grasping chances. "Genius for business," someone has said, "consists in
making exact hypotheses regarding the fluctuations of values." To
characterize the mental state is easy, if it is a matter merely of
giving examples; very difficult, if one attempts to discover its
mechanism.

The physician who in a trice diagnoses a disease, who, on a higher
level, groups symptoms in order to deduce a new disease from them, like
Duc