|S. Austin Allibone, comp. Prose Quotations from Socrates to Macaulay. 1880.|
| The word perception is, in the language of philosophers previous to Reid, used in a very extensive signification. By Descartes, Malebranche, Locke, Leibnitz, and others, it is employed in a sense almost as unexclusive as consciousness, in its widest signification. By Reid this word was limited to our faculty acquisitive of knowledge, and to that branch of this faculty whereby, through the senses, we obtain a knowledge of the external world. But his limitation did not stop here. In the act of external perception he distinguished two elements, to which he gave the names of perception and sensation. He ought perhaps to have called these perception proper and sensation proper, when employed in his special meaning.|
Sir William Hamilton.
| Perception is only a special kind of knowledge, and sensation a special kind of feeling
. Knowledge and feeling, perception and sensation, though always co-existent, are always in the inverse ratio of each other.|| 2|
| Apprehension, in logic, is that act or condition of the mind in which it receives the notion of any object, and which is analogous to the perception of the senses.|