Deontology is a major normative ethical theory that evaluates the morality of actions based on whether they adhere to certain rules or duties, rather than on the consequences those actions produce. The term derives from the Greek words deon (duty) and logos (science or study), emphasizing a focus on the inherent rightness or wrongness of actions themselves. Core Principles Rule-Based Ethics: Deontology holds that actions are morally obligatory, permissible, or forbidden according to a clear set of rules or duties. If an action aligns with these rules, it is considered ethical; if not, it is unethical. Duty for Duty’s Sake: Actions are right or wrong in themselves, regardless of the outcomes they produce. This is often summarized by phrases like “duty for duty’s sake” and “let justice be done though the heavens fall”. Contrast with Consequentialism: Unlike consequentialist theories (such as utilitarianism), which judge actions by their outcomes, deontology asserts that some actions are intrinsically right or wrong, independent of their consequences. This essay explores whether deontology should be used to determine morality.