thoughtful vs thoughtfulness

thoughtful is not a noun while thoughtfulness is a noun.

Word	Noun	Adjective	Verb	Adverb
thoughtful	No	Yes	No	No
thoughtfulness	Yes	No	No	No

thoughtful (noun)	thoughtfulness (noun)
	a considerate and thoughtful act
	the trait of thinking carefully before acting
	kind and considerate regard for others
	a calm, lengthy, intent consideration

thoughtful (adjective)	thoughtfulness (adjective)
exhibiting or characterized by careful thought
taking heed; giving close and thoughtful attention
considerate of the feelings or well-being of others
having intellectual depth
characterized by solemn, sincere manner