Perception, n.
Etymology: [L. perceptio: cf. F. perception. See Perceive.]
1. The act of perceiving; cognizance by the senses or intellect; apperhension by the bodily organs, or by the mind, of what is presented to them; discernment; apperhension; cognition.
2. (Metaph.)
The faculty of perceiving; the faculty, or peculiar part, of man's constitution by which he has knowledge through the medium or instrumentality of the bodily organs; the act of apperhending material objects or qualities through the senses; -- distinguished from conception. Sir W. Hamilton. Matter hath no life nor perception, and is not conscious of its own existence. Bentley.
3. The quality, state, or capability, of being affected by something external; sensation; sensibility. [Obs.] This experiment discovereth perception in plants. Bacon.
2 more senses
4. An idea; a notion. [Obs.] Sir M. Hale.
Note: "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 W. Hamilton.
Shades of meaning
Fernald has no entry of its own for perception; he lists it under knowledge, sensation.
Where he writes about it:
We speak of perception of external objects, apprehension of intellectual truth. — from knowledge
Simple perception gives a limited knowledge of external objects, merely as such; the cognition of the same objects is a knowledge of them in some relation; cognizance is the formal or official recognition of something as an object of knowledge; we take cognizance of it. — from knowledge
Sensation is the mind's consciousness due to a bodily affection, as of heat or cold; perception is the cognition of some external object which is the cause or occasion of the sensation; the sensation of heat may be connected with the perception of a fire. — from sensation
A sense is an organ or faculty of sensation or of perception. — from sensation