things. Astrology groups into "constellations" stars that are billions
of miles apart, believes that it discovers there an animal shape, human
or any other, and deduces therefrom alleged "influences." This star is
reddish (Mars), sign of blood; this other is of a pure, brilliant
silvery light (Venus) or livid (Saturn), and acts in a different way. We
know what clever structures of conjectures and prognoses have been built
on these foundations. Need we mention the Middle Age practice of charms,
which even in our day still has adherents among cultured people? The
physicians of the time of Charles II, says Lang, gave their patients
"mummy powder" (pulverized mummies) because the mummies, having lasted a
long time, must prolong life.[121] Gold in solution has been esteemed
as a medicine--gold, being a perfect substance, should produce perfect
health. In order to get rid of a disease nothing is more frequent among
primitive men than to picture the sick person on wood or on the ground,
and to strike the injured part with an arrow or knife, in order to
annihilate the sickening principle.

(3) Finally, there is the magic influence ascribed to certain words. It
is the triumph of the theory of _nomina numina_; we need not return to
it. But the working of the mind on words, erecting them into entities,
conferring life and power on them--in a word, the activity that creates
myths and is the final basis of all constructive imagination--appears
also here.[122]

II

Up to this point we have considered the practical imagination only in
its somewhat petty aspect in small inventions or as semi-morbid in
superstitious fancies. We now come to its higher form, mechanical
invention.

This subject has not been studied by psychologists. Not that they have
misunderstood its role, which is, after all, very evident; but they
limit themselves to speak of it cursorily, without emphasizing it.

In order to appreciate its importance, I see no other way than to put
ourselves face to face with the works that it has produced, to question
the history of discovery and useful arts, to profit by the disclosures
of inventors and their biographers.

Of a work of this kind, which would be very long because the materials
are scattered, we can give here only a rough sketch, merely to take
therefrom what is of interest for psychology and what teaches us in
regard to the characters peculiar to this type of imagination.

The erroneous view that opposes im