“ In psychology quality is especially distinguished from intensity, duration, and, in the case of special perceptions, from extension, as an attribute of sensation, and it furnishes the only test for distinguishing kinds of sensations. Of course, in ordinary experience qualities come to us fused, such a thing as a pure quality being seldom, if ever, experienced. ”

“ Quality has, in modern philosophy, a psychological connotation, denoting characteristics of perception as much as of real things. It is thus the individual attribute of sensation, that which characterizes or individualizes one kind of sensation so that it cannot possibly be mistaken for any other kind—redness, nausea, hunger, triangularity, are examples of quality. ”

“ Things are made up of compositions of qualities, and these compositions, in a certain sense, may themselves be considered as qualities in that they form the qualitative texture of actual experience and are the basis for our discriminations of things. ”