An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

OR SCIENTIFIC METHOD. 305
genius in science as well as in poetry and art ; and the
scientific genius stands out clearly from the common
run of scientific workers. To such a mind, trained by
previous observation and thought, a few facts will
suggest, almost as if by inspiration, hypotheses of far-
reaching importance. This is what Tyndall expressed
in the passage so often quoted from an essay on
"
The
Scientific Use of the Imagination," in his Fragments of
Science. "With accurate experiment and observation
to work upon, imagination becomes the architect of
physical theory. Newton s passage from a falling apple
to a falling moon was an act of the prepared imagina
tion ; out of the facts of chemistry the constructive
imagination of Dalton formed the atomic theory ; Davy
was richly endowed with the imaginative faculty, while
with Faraday its exercise was incessant, preceding,
accompanying, and guiding all his experiments. . . .
Without the exercise of this power, our knowledge of
Nature would be a mere tabulation of coexistences and
sequences,"
Nevertheless, every hypothesis must be based on
facts. It is suggested only because it is a possible
explanation of the facts. It is not created by the
scientific imagination "out of nothing"; it is not in
dependent of facts, as are the impulses of the artistic
imagination. It is intimately dependent, as Tyndall says,
on the suggestions of accurate experiment and observation,
and also on whatever knowledge the investigator already
possesses. His previous acquaintance with the subject
suggests the limits within which probable hypotheses
must lie, and opens his eyes to obscure analogies and
insignificant residual phenomena to which the ordinary
mind would pay no attention. And as in its origin it
depends upon facts,
so for its verification we must
u