skepticism vs mental rejection

skepticism and mental rejection both are nouns.

Word	Noun	Adjective	Verb	Adverb
skepticism	Yes	No	No	No
mental rejection	Yes	No	No	No

As nouns, skepticism and mental rejection are synonyms defined as:

Other synonyms of skepticism include disbelief, incredulity, scepticism.

skepticism (noun)	mental rejection (noun)
doubt about the truth of something	doubt about the truth of something
the disbelief in any claims of ultimate knowledge