Quality

Sensible qualities belong to the world of becoming; the Forms, which truly are, stand beyond hot and cold, sweet and bitter.

Quality is one of the ten categories of being: it names what a thing is like, from habits and dispositions to colors, shapes, and capacities.

Quality perfects substance in its manner of being; habits and dispositions are qualities of the soul that order it toward its proper operation.

Qualities are nothing in the object itself but motions; what we call color, sound, and heat are phantasms produced in us by external pressure.

Extension, figure, and motion belong to bodies as they are; color, sound, and warmth exist only in the perceiving mind.

Primary qualities (solidity, extension, motion, number) resemble their causes in objects; secondary qualities (color, sound, taste) are powers to produce ideas in us.

We have no basis for distinguishing what is truly in objects from what is in us; the line between primary and secondary qualities cannot be drawn.

Quality enters experience through the Anticipations of Perception: every sensation has an intensive magnitude, a degree, that belongs to the form of experience rather than to things in themselves.

Quality is the first determination of being: being, as immediately determined, is quality, and to lose its quality is to cease to be what it is.