Definition by exhaustive negation of qualities
Reinhardt defines art-as-art mainly by listing what it must not contain: no texture, no brushwork, no drawing, no forms, no design, no colors, no light, no space, no time, no size, no movement, no object, no subject. Each negation removes one channel through which something other than art (illustration, expression, decoration, commerce) can get in. What survives the full list is the thing itself, so the list works as a discipline for purifying a practice rather than as a style guide.