|Qualities, philosophy: quality is an expression of the nature of objects or the form of properties. Today, it is no longer understood as a category but rather as the sum of the distinguishing features of an object. Properties of the objects like their size, mass, etc. count as objective or primary qualities, subjective (secondary) qualities are properties which are settled in the subject, e.g. color. See also quantities, qualia, subjectivity, objectivity, properties, features.|
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|Holz I 46
Quality/Leibniz: simple qualities, e.g. colors, odors, taste are expressible only by themselves and not by other characteristics. They are not further provable. (Since they cannot be traced back to simpler components (qua definition) by the identity principle).
The simple sense qualities are "projections" (like parabola to the circle, each point of one side corresponds to one of the others). That is, that they are not to be regarded as identical expressions of the reality corresponding to them.
G. W. Leibniz
Philosophical Texts (Oxford Philosophical Texts) Oxford 1998
H. H. Holz
Leibniz Frankfurt 1992