How this metamorphosis takes place; how a force existing, as motion, heat, or light, can become a mode of consciousness; how it is possible for aerial vibrations to generate the sensation we call sound; or for the forces liberated by chemical changes in the brain to give rise to emotion,—these are mysteries which it is impossible to fathom.”
You may apply as much physical force by means of a galvanic battery to a dead brain as you please, but you can’t strike an idea out of it; and this vital force, while it is “conditioned force,” like light and heat, differs in its mode of manifestation from every other manifestation of force, even more than they do from each other, in that it possesse
certain chemical action in the brain by which it becomes converted into thought or emotion, into love or philosophy, into art or religion, as the case may be: what the nature of that love or philosophy, or art or religion, may be, must depend entirely on the nature of the chemical change.
