In philosophy, a quality is an attribute or
a property characteristic of an object.
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.John Locke presented a distinction
between primary and secondary qualities in
An Essay Concerning Human Understanding.
For Locke, a quality is an idea of a sensation
or a perception.
Locke further asserts that qualities can be
divided in two kinds: primary and secondary
qualities.
Primary qualities are intrinsic to an object—a
thing or a person—whereas secondary qualities
are dependent on the interpretation of the
subjective mode and the context of appearance.
For example, a shadow is a secondary quality.
It requires a certain lighting to be applied
to an object.
For another example, consider the mass of
an object.
Weight is a secondary quality since, as a
measurement of gravitational force, it varies
depending on the distance to, and mass of,
very massive objects like the Earth, as described
by Newton's law.
It could be thought that mass is intrinsic
to an object, and thus a primary quality.
In the context of relativity, the idea of
mass quantifying an amount of matter requires
caution.
The relativistic mass varies for variously
traveling observers; then there is the idea
of rest mass or invariant mass (the magnitude
of the energy-momentum 4-vector), basically
a system's relativistic mass in its own rest
frame of reference.
(Note, however, that Aristotle drew a distinction
between qualification and quantification;
a thing's quality can vary in degree).
Only an isolated system's invariant mass in
relativity is the same as observed in variously
traveling observers' rest frames, and conserved
in reactions; moreover, a system's heat, including
the energy of its massless particles such
as photons, contributes to the system's invariant
mass (indeed, otherwise even an isolated system's
invariant mass would not be conserved in reactions);
even a cloud of photons traveling in different
directions has, as a whole, a rest frame and
a rest energy equivalent to invariant mass.
Thus, to treat rest mass (and by that stroke,
rest energy) as an intrinsic quality distinctive
of physical matter raises the question of
what is to count as physical matter.
Little of the invariant mass of a hadron (for
example a proton or a neutron) consists in
the invariant masses of its component quarks
(in a proton, around 1%) apart from their
gluon particle fields; most of it consists
in the quantum chromodynamics binding energy
of the (massless) gluons (see Quark#Mass).
== Conceptions of quality as metaphysical
and ontological ==
Philosophy and common sense tend to see qualities
as related either to subjective feelings or
to objective facts.
The qualities of something depends on the
criteria being applied to and, from a neutral
point of view, do not determine its value
(the philosophical value as well as economic
value).
Subjectively, something might be good because
it is useful, because it is beautiful, or
simply because it exists.
Determining or finding qualities therefore
involves understanding what is useful, what
is beautiful and what exists.
Commonly, quality can mean degree of excellence,
as in, "a quality product" or "work of average
quality".
It can also refer to a property of something
such as "the addictive quality of nicotine".
In his book, Zen and the Art of Motorcycle
Maintenance, Robert M. Pirsig examines concepts
of quality in classical and romantic, seeking
a Metaphysics of Quality and a reconciliation
of those views in terms of non-dualistic holism.
== References ==
== External links ==
"Quality".
New International Encyclopedia.
1905.
