constructive vs constructiveness

constructive is not a noun while constructiveness is a noun.

Word	Noun	Adjective	Verb	Adverb
constructive	No	Yes	No	No
constructiveness	Yes	No	No	No

constructive (noun)	constructiveness (noun)
	the quality of serving to build or improve

constructive (adjective)	constructiveness (adjective)
constructing or tending to construct or improve or promote development
emphasizing what is laudable or hopeful or to the good