casuist vs casuistical

casuist is a noun but casuistical is not a noun.

Word	Noun	Adjective	Verb	Adverb
casuist	Yes	No	No	No
casuistical	No	Yes	No	No

casuist (noun)	casuistical (noun)
someone whose reasoning is subtle and often specious

casuist (adjective)	casuistical (adjective)
	of or relating to the use of ethical principles to resolve moral problems
	of or relating to or practicing casuistry