The quality of being classical; the state or character of possessing classical attributes or conforming to classical standards.
From 'classical' + '-ness' (quality or state). The '-ness' suffix is one of the most productive in English for creating abstract nouns from adjectives.
The 'classicalness' of a Greek temple versus a Gothic cathedral shows how these words let us compare whole aesthetic systems—it's a way of saying 'this thing carries the weight of what classical means' without getting into all the details.
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