Quality

Quality may refer to:

Concepts

Music

Businesses

Quality (philosophy)

A quality (from Latin qualitas) is an attribute or a property. In contemporary philosophy the idea of qualities, and especially how to distinguish certain kinds of qualities from one another, remains controversial.

Background

Aristotle analyzed qualities in his logical work, the Categories. To him, qualities are hylomorphically–formal attributes, such as "white" or "grammatical". Categories of state, such as "shod" and "armed" are also non–essential qualities (katà symbebekós). Aristotle observed: "one and the selfsame substance, while retaining its identity, is yet capable of admitting contrary qualities. The same individual person is at one time white, at another black, at one time warm, at another cold, at one time good, at another bad. This capacity is found nowhere else... it is the peculiar mark of substance that it should be capable of admitting contrary qualities; for it is by itself changing that it does so". Aristotle described four types of qualitative opposites: correlatives, contraries, privatives and positives.

Quality (physics)

In response theory, the quality of an excited system is related to the number of excitation frequencies to which it can respond. In the case of a homogeneous, isotropic system, the quality is proportional to the FWHM.

This sense of the phrase is the precursor of the usage of the word in music theory. In music theory, quality is the number of harmonics of a fundamental frequency of an instrument (the higher the quality, the richer the sound).

See also