Note 802 — Chapter XXIX
Reading edition
L. vi., c. 4. All conceptions of abstract ideas, he justly remarks in another place, are accompanied with some imagination, though we are often not aware of it; because these ideas have no natural images or traces associated with them, but such only as the will of man or chance has given. Thus, in analysis, however general the ideas, we use letters and signs, always associated with the ideas of the things, though they are not really related, and for this reason do not give us false and confused notions. Hence, he thinks, the ideas of things which can only be perceived by the understanding, may become associated with the traces on the brain, l. v., c. 2. This is evidently as applicable to language as it is to algebra.