casuistry vs ethics

casuistry and ethics both are nouns.

Word	Noun	Adjective	Verb	Adverb
casuistry	Yes	No	No	No
ethics	Yes	No	No	No

As nouns, ethics is a hypernym of casuistry; that is, ethics is a word with a broader meaning than casuistry:

casuistry: moral philosophy based on the application of general ethical principles to resolve moral dilemmas
ethics: the philosophical study of moral values and rules

Other hypernyms of casuistry include moral philosophy.

casuistry (noun)	ethics (noun)
moral philosophy based on the application of general ethical principles to resolve moral dilemmas	the philosophical study of moral values and rules
argumentation that is specious or excessively subtle and intended to be misleading	motivation based on ideas of right and wrong