theory of gravitation vs natural philosophy

theory of gravitation and natural philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
theory of gravitation	Yes	No	No	No
natural philosophy	Yes	No	No	No

theory of gravitation (noun)	natural philosophy (noun)
(physics) the theory that any two particles of matter attract one another with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them	the science of matter and energy and their interactions