Reasons

Reasons are considerations that count in favor of a belief, a decision, or an action. They function as grounds for justification and as explanations of behavior. In everyday language a reason is what someone cites to support what they think or do; in philosophy the term is used with more precision, including evidential reasons for beliefs, normative reasons for actions, and explanatory reasons for states of mind.

Reasons for belief typically depend on evidence, testimony, or argument. They aim to support the truth of a proposition. Reasons for action depend on a person’s values, desires, duties, and context. A person may have reasons to act that are internal to their framework of goals and commitments, or external, arising from social or legal expectations. The strength of a reason can vary with the agent and the circumstances.

Philosophers distinguish among causal explanations and normative justifications. Causes explain how events unfold; reasons justify why an agent acts in a given situation. Some accounts treat reasons as causes of actions, while others reserve “reason” for normative considerations that bear on rational decision making. A common distinction is between internal reasons, which depend on the agent’s perspective and evidence, and external reasons, which may exist independently of what the agent knows or values.

Normative reasons matter for rational agency. They are reasons that, given an agent’s goals and obligations, ought to influence belief and action. Moral, prudential, and logical considerations can all count as reasons, though they may carry different weight in different ethical or epistemic frameworks.

Across disciplines, the concept of a reason links evidence, justification, and intention. Law, science, and everyday life rely on reasons to explain, defend, and decide.