John Tyndall Quote

We observe facts and store them up; imagination broods upon these memories, and by the aid of reason tries to discern their interdependence. The theoretic principle flashes, or slowly dawns upon the mind, and then the deductive faculty interposes to carry out the principle to its logical consequences.

Fragments of Science for Unscientific People, Chapter XIII (p. 366), D. Appleton & Co. 1875