rigor vs cogency

rigor and cogency both are nouns.

Word	Noun	Adjective	Verb	Adverb
rigor	Yes	No	No	No
cogency	Yes	No	No	No

As nouns, rigor and cogency are synonyms defined as:

Other synonyms of rigor include rigour, validity.

rigor (noun)	cogency (noun)
something hard to endure	the quality of being valid and rigorous
the quality of being valid and rigorous	persuasive relevance
excessive sternness