justness vs natural virtue

justness and natural virtue both are nouns.

Word	Noun	Adjective	Verb	Adverb
justness	Yes	No	No	No
natural virtue	Yes	No	No	No

As nouns, natural virtue is a hypernym of justness; that is, natural virtue is a word with a broader meaning than justness:

justness: the quality of being just or fair
natural virtue: (scholasticism) one of the four virtues (prudence, justice, fortitude, and temperance) derived from nature

Other hypernyms of justness include righteousness.

justness (noun)	natural virtue (noun)
the quality of being just or fair	(scholasticism) one of the four virtues (prudence, justice, fortitude, and temperance) derived from nature
conformity with some esthetic standard of correctness or propriety