Note 23 — Chapter II
Reading edition
"Sensorial impression is at the bottom of all our ideas, all our conceptions, though it may at first conceal itself in the form of a binary, ternary, quaternary compound; and, on our methodically pursuing the inquiry, it is easily recognizable—just as a simple substance in organic chemistry may be always summoned to appear, if we sit down with the resolution to disengage it from all the artificial combinations which hold it imprisoned."—Luys, The Brain and its Functions, p. 252.