natural philosophy vs incoherent

natural philosophy is a noun but incoherent is not a noun.

Word	Noun	Adjective	Verb	Adverb
natural philosophy	Yes	No	No	No
incoherent	No	Yes	No	No

natural philosophy (noun)	incoherent (noun)
the science of matter and energy and their interactions

natural philosophy (adjective)	incoherent (adjective)
	without logical or meaningful connection
	(physics) of waves having no stable definite or stable phase relation
	unable to express yourself clearly or fluently