Aristotle - The Organon - index for CATEGORIAE Book 1 Part 8

Quality

Paragraph 1	By 'quality' I mean that in virtue of which people are said to be such and such.
Paragraph 2	Quality is a term that is used in many senses.
Paragraph 3	By a disposition, on the other hand, we mean a condition that is easily changed and quickly gives place to its opposite.
Paragraph 4	It is evident that men incline to call those conditions habits which are of a more or less permanent type and difficult to displace;
Paragraph 5	Habits are at the same time dispositions, but dispositions are not necessarily habits.
Paragraph 6	Another sort of quality is that in virtue of which, for example, we call men good boxers or runners, or healthy or sickly:
Paragraph 7	A third class within this category is that of affective qualities and affections.
Paragraph 8	The term 'affective quality' is not used as indicating that those things which admit these qualities are affected in any way.
Paragraph 9	Whiteness and blackness, however, and the other colours, are not said to be affective qualities in this sense, but - because they themselves are the results of an affection.
Paragraph 10	Those conditions, however, which arise from causes which may easily be rendered ineffective or speedily removed, are called, not qualities, but affections:
Paragraph 11	Thus such conditions are called affections, not qualities.
Paragraph 12	In like manner there are affective qualities and affections of the soul.
Paragraph 13	Those, however, which arise from causes easily rendered ineffective are called affections, not qualities.
Paragraph 14	The fourth sort of quality is figure and the shape that belongs to a thing;
Paragraph 15	Rarity and density, roughness and smoothness, seem to be terms indicating quality:
Paragraph 16	There may be other sorts of quality, but those that are most properly so called have, we may safely say, been enumerated.
Paragraph 17	These, then, are qualities, and the things that take their name from them as derivatives, or are in some other way dependent on them, are said to be qualified in some specific way.
Paragraph 18	There are some cases, however, in which, as the quality under consideration has no name, it is impossible that those possessed of it should have a name that is derivative.
Paragraph 19	We may therefore state that those things are said to be possessed of some specific quality which have a name derived from that of the aforesaid quality, or which are in some other way dependent on it.
Paragraph 20	One quality may be the contrary of another;
Paragraph 21	If one of two contraries is a quality, the other will also be a quality.
Paragraph 22	Qualities admit of variation of degree.
Paragraph 23	Though this is generally the case, there are exceptions.
Paragraph 24	The qualities expressed by the terms 'triangular' and 'quadrangular' do not appear to admit of variation of degree, nor indeed do any that have to do with figure.
Paragraph 25	Whereas none of the characteristics I have mentioned are peculiar to quality, the fact that likeness and unlikeness can be predicated with reference to quality only, gives to that category its distinctive feature.
Paragraph 26	We must not be disturbed because it may be argued that, though proposing to discuss the category of quality, we have included in it many relative terms.
Paragraph 27	Thus individual branches of knowledge are not relative.