"Ought not" is a phrase used to express a recommendation or moral obligation against doing something. It suggests that a particular action is not advisable or is considered wrong. For example, one might say, "You ought not to lie," indicating that honesty is the preferred choice. In discussions of ethics and morality, "ought not" often reflects societal norms or personal values. It can be used in various contexts, such as in debates about law, social behavior, or personal decisions. Understanding this phrase helps clarify expectations and responsibilities in different situations.