Abstract ideas (n.) as partial ideas of more complex ones are all that general natures are, and he who looks for them anywhere else will be at a loss where to find them.
Abstract ideas (n.) are the bonds between particular things and the names they are ranked under — the medium that ties a word to the world.
Abstract ideas (n.) are the measures of names and the boundaries of species.
Abstract ideas (n.) however remote they seem from sense are only such as the understanding frames by repeating and joining ideas from objects of sense or from its own operations about them.
An Abstract ideas (n.) of a triangle must be neither oblique nor rectangle, equilateral nor scalene, but all and none of these at once — something imperfect that cannot exist.
An Abstract ideas (n.) is a mark of our imperfection: the mind hurries toward such ideas for communication and the growth of knowledge, but needs them only because it is limited.