perceptiveness vs perceptive

perceptiveness is a noun but perceptive is not a noun.

Word	Noun	Adjective	Verb	Adverb
perceptiveness	Yes	No	No	No
perceptive	No	Yes	No	No

perceptiveness (noun)	perceptive (noun)
the quality of insight and sympathetic understanding
delicate discrimination (especially of esthetic values)
perception of that which is obscure
a feeling of understanding

perceptiveness (adjective)	perceptive (adjective)
	having the ability to perceive or understand; keen in discernment
	of or relating to perception