An Idea (n.) is everything that is an object of thought. An idea is that which one is immediately conscious of within himself.
The Idea (n.) when it is determined replaces clear and distinct, words familiar in men's mouths that not everyone who uses them perfectly understands, and it is an object of the mind annexed without variation to one name.
An Idea (n.) is whatever the mind can be employed about in thinking — phantasm, notion, species, all at once.
Idea (n.) and notions are no more born with us than arts and sciences.
An Idea (n.) is a sensation you cannot have without the thing: a child kept among black and white till manhood has no more idea of scarlet than a man who never tasted a pineapple has of its relish.
An Idea (n.) of sensation is no more a likeness of something outside us than a name is a likeness of the idea it excites.
Idea (n.) of our youth, like our children, often die before us.
Idea (n.) succeed one another in the waking mind at a roughly fixed pace, like the images in a lantern turned round by the heat of a candle.
An Idea (n.) of a thing no more proves the thing exists than a man's picture proves he is in the world, or a dream makes a true history.
The Idea (n.) of a chiliaedron, a body of a thousand sides, can be clear as to number while its figure cannot be told from one of 999 sides.
The Idea (n.) of a substance is an ectype, an imperfect copy, which can never be sure it holds everything in the thing.
An Idea (n.) taken by itself is no more true or false than a single name is; falsehood starts only when the mind affirms or denies something of it.