right and wrong; merits and demerits
Formal yojijukugo used to discuss the justice or fairness of a matter, often in legal or ethical contexts.
In a trial, it is required to clarify the rights and wrongs of the case.
He argued emotionally without discerning right from wrong.
是非 is a more common word for right and wrong, used in everyday contexts, while 理非曲直 is a formal, literary yojijukugo.
善悪 refers to good and evil in a moral sense, whereas 理非曲直 focuses on logical or legal rightness.
A yojijukugo composed of 理 (reason), 非 (wrong), 曲 (crooked), and 直 (straight), literally meaning 'reason and wrong, crooked and straight', i.e., the rights and wrongs of a matter.