Reason (argument)
In philosophy and argumentation, a reason is a consideration that counts in favor of a conclusion, action, attitude or fact, or that explains why something is so. Reasons typically answer a why? question and are often introduced by expressions such as because, since, as, in virtue of, or in order to. They are central to accounts of practical reason, epistemic justification, moral evaluation, and everyday explanation, and they figure prominently in law and deliberative discourse.
Philosophers commonly distinguish three roles for reasons. Normative reasons are considerations that count in favor of responding one way rather than another. Motivating reasons are the considerations in light of which an agent acts—what the agent treats as counting in favor at the time, whether or not it in fact does. Explanatory reasons cite what explains an event or action; when agents are involved, these often refer to psychological states.
Debates concern what reasons are and how they work. Some hold that normative reasons are facts rather than mere beliefs; others link them more closely to an agent's perspective. Reasons are said to play both a deontic role and a deliberative role. Further questions include whether acting rightly must be done for the right reasons to have moral worth, and how normative and motivating reasons are related when guidance is difficult.
The literature also distinguishes epistemic reasons from practical reasons, and asks whether there is a unified treatment of both—e.g., by understanding reasons as a kind of evidence. Disputes about the source of practical reasons are framed as internalism versus externalism: internalists tie a person's reasons to their actual or idealized motivational set, while externalists allow that there can be reasons independent of an agent's present motivations. A separate contrast between agent-neutral and agent-relative reasons concerns whether the content of a reason makes essential reference to the agent or not.
Because agents often face multiple, context-sensitive considerations, contemporary work analyzes how reasons are weighed, defeated, or enabled. Proposals address holism about reasons, pairwise and contrastive frameworks for permissibility, possible incommensurability or parity among options, and distinctions between justifying and requiring strengths. Related topics include exclusionary reasons that bar acting for certain first-order reasons, and questions about aggregating overlapping considerations. These issues connect the concept of a reason to broader discussions in ethics, rational choice, epistemology, and the theory of argument.
Types of reason
Many contemporary accounts start from a threefold classification.; Normative reasons
; Motivating reasons
; Explanatory reasons
Normative reasons
Roles: deontic and deliberative
Normative reasons play at least two roles. In their deontic role, they help settle what one ought/must/may do by weighing reasons for and against actions. In their deliberative role, they are the appropriate inputs to sound deliberation and can become motivating reasons when an agent responds to them.Ontology and objectivity
A common view holds that normative reasons are facts, not merely beliefs; some identify them with true propositions, others with worldly states of affairs. Authors also distinguish between objective reasons and subjective or apparent reasons.What it is for a fact to be a reason
Competing characterizations include:Deontic-explanatory: a reason is what figures on the for side of an explanation of why one ought to act.Deliberative-premise: reasons are the premises of good reasoning.Ends-based: reasons relate actions to ends, either to agents' desires or to value/the good.Weighing, defeat, and constraints
Reason-weighing is often modeled by metaphors of weight/strength, but holism, context-sensitivity, and incommensurability complicate simple additive pictures. Some argue for epistemic constraints on the reasons relevant to what one ought to do, while others retain an objective ought sensitive to all the facts. Classic puzzle cases illustrate the tension.Motivating and explanatory reasons
Philosophers distinguish an agent's motivating reason from the fact that explains their action. For example, Othello kills Desdemona for the consideration that she was unfaithful, while what explains his action includes that he believed she was unfaithful.What kind of thing is a motivating reason?
Debate centers on whether motivating reasons are:Mental states : reasons are desire–belief pairs that cause action;Facts : the reason for which one acts is fact;Propositions: what one acts for is the content believed, true or false.A widely discussed constraint says that one must be able to act for a good reason; this pressures psychologism if mental states as such cannot be good reasons. There is also debate over the epistemic condition for acting in the light of a fact—some argue that mere true belief is insufficient and that knowledge is required; others resist this requirement.
''Guise'' theses
On guise of the good/''guise of reasons'' views, acting for a reason involves taking a consideration as favoring the action. Alleged counterexamples have prompted refinements.The relation between normative and motivating reasons
A natural idea is that normative reasons are supposed to guide us. This is developed as: a deliberative condition, an ability condition, or a combined condition. Puzzles about self-effacing reasons challenge simple guidance theses and motivate careful distinctions between deontic and deliberative roles.Acting for a normative reason and moral worth
Sometimes one does the right thing but not for the right reason. Many hold that moral worth/credit requires acting for the very reasons that make the action right—or from the right kind of concern or normative knowledge.Epistemic versus practical reasons
Philosophers distinguish capacities of theoretical and practical reason. Epistemic reasons count in favor of believing a proposition; practical reasons count in favor of actions or attitudes. Some propose a unified treatment—e.g., that reasons are a kind of evidence across domains. In argumentation, a reason may be a premise supporting a conclusion; explanatory reasons can clarify how something could be true without by themselves showing that it is true.Internalism and externalism about practical reasons
In debates about practical reason, philosophers ask whether there is a necessary connection between an agent's normative reasons and the agent's motivation. Reasons internalism holds that for a consideration to be a reason for an agent, it must stand in some privileged relation to facts about that agent's motivation or motivational psychology; reasons externalism denies any such necessary connection. Although framed about action, these positions bear on broader issues about normativity, rationality, and moral obligation.Varieties
Scholars distinguish several axes along which internalist theses vary.; Motivation vs. state views
; Actual vs. counterfactual conditions
; Direction of explanation
The Humean theory and a central tension
A prominent actual-state thesis is the Humean Theory of Reasons : one has a reason to perform an action only if doing it would serve some actual desire of one's own. It is commonly paired with the Humean Theory of Motivation that desires are necessary and beliefs not sufficient for motivation. Critics argue that HTR conflicts with two widely held assumptions: moral rationalism and moral absolutism. Together these suggest there are reasons independent of an agent's actual desires. Responses include rejecting absolutism or rationalism, or weakening internalism to counterfactual forms that do not depend on an agent's present psychology.Arguments and objections
; Motivational/explanatory links; Analogy to theoretical reason
; Reactive attitudes
; The "conditional fallacy"
Extensional (case-based) considerations
Critics argue internalist theses can undergenerate reasons: e.g., we seem to have prudential reasons now even if we presently lack supporting desires; internalists reply with overdetermination strategies or by challenging the data. Conversely, simple desire-based views appear to overgenerate ; internalists often treat desire as a necessary but not sufficient condition, or else appeal to background standards filtering which desires yield reasons.Contemporary landscape
Recent work explores whether counterfactual internalisms can avoid triviality without reverting to actual psychology, and whether externalist accounts can explain both categorical moral reasons and the everyday desire-sensitivity of many reasons; anthologies collect competing approaches and clarifications.Agent-relative and agent-neutral reasons
Scholars often distinguish between agent-neutral and agent-relative normative reasons—two patterns by which considerations favor actions. On a classic principle-based view, a reason is agent-neutral when the associated principle contains no non-trivial reference to the agent for whom it is a reason; it is agent-relative when such reference is essential to the reason-giving condition. Thus, impartial welfare-maximizing considerations are standardly treated as agent-neutral, whereas egoistic reasons or special-relationship reasons are agent-relative.Alternative formulations
Other ways of drawing the line have been proposed. On a reason-statement approach, a reason is agent-relative iff a full statement of that reason must use pronominal back-reference to the very agent for whom it is a reason. A different, perspective-based approach ties neutrality to whether reasons can be recognized from suitably objective standpoints, and takes some reasons to be appreciable only from more first-personal perspectives. Each formulation faces pressures: the reason-statement view depends on contentious assumptions about irreducibly indexical facts, while the perspective view makes classification hinge on controversial theses about objectivity.Default principles, holism, and particularism
Many hold that reasons are holistic and context-sensitive: what counts in favor in one case may be silenced or reversed in another by defeaters; some background conditions are mere enablers rather than reasons themselves. To accommodate this holism while retaining the clarity of the principle-based distinction, some theorists use default principles—hedged generalizations that say, roughly, "F is a reason for p to φ unless some feature of the situation explains why not." On this picture, neutrality vs relativity turns on whether the reason-clause contains a non-trivial free agent variable. Objections that such principles are vacuous are answered by noting that the "feature of the situation" is constrained to be contingent, not any necessary truth, so the hedging does real explanatory work rather than trivializing the claim.Related distinctions and common confusions
Several nearby distinctions are sometimes conflated with the agent-neutral/agent-relative divide:Internal vs external reasons is about the source of normative force, not about agent-indexing in the content of a reason.Universality concerns scope/form of principles and rigid designators, not whether reasons are indexed to agents.Deliberator-relative vs deliberator-neutral principles focus on which norms a rational agent must recognize, rather than on the form of the reason-giving condition.Appraiser-relativism relativizes truth to the evaluator, not the agent of action.Essentially shared and intersubjective reasons track whether reasons supply reasons for others or are communicable; they need not coincide with neutrality/relativity, and teleological assumptions can obscure the difference.Significance for normative theory
The distinction structures debates about consequentialism and deontology. Deontic constraints can be modeled via agent-relative teleological reasons, a strategy used to "consequentialize" deontological theories in structural terms. It also highlights surprising asymmetries—e.g., maximizing expected utility can introduce agent-relativity via whose expectations count. The distinction has been central in work on expressivism about normativity, and in Kantian attempts to vindicate deontic prohibitions without agent-relative value.Weighing reasons and related debates
Many theorists analyze how multiple considerations interact to determine what is permissible, required, or best by appealing to the weighing of reasons. On this approach, reasons function as direct contributors to a verdict, while various contextual features can indirectly enable, disable, amplify, or attenuate the relevance of those reasons.Pairwise frameworks and contrastivism
A widely discussed template—sometimes called Monist Pairwise Permissibility—says an option φ is permissible iff, for each alternative, the reasons for φ are not outweighed by the reasons for that alternative. This treats permissibility as a "tournament" of pairwise comparisons rather than a free-for-all among all reasons at once.Within this framework, some defend contrastive reasons, whose weight varies with the specific alternative under consideration. Contrastivism has been developed for practical and epistemic cases and used to explain puzzling triads like Kamm's "Café or Kid" case, where what competes with promise-keeping changes once a third option is introduced.
For-and-against, option individuation, and maximalism
On one influential view, talk of a "reason against" φ just is talk of a "reason for" some specified alternative to φ in the same pairwise contest; which locution we use depends on explanatory emphasis.How we individuate options matters to weighing. Maximalism holds that reasons fundamentally apply to maximal, mutually exclusive and exhaustive options, and that permissibility for coarser options derives from verdicts about these maximal ones.
Holism, conditions, and modifiers
Against atomism, holism claims that context can change whether something is a reason at all or how weighty it is. Examples include coerced promises and special relationships.Incommensurability, parity, and moral options
To explain widespread and stable cases where more than one option is permissible, some reject strict trichotomy and allow parity: two options can be comparable without being precisely equal; small improvements need not break parity. Others worry parity alone cannot preserve permissible partiality or supererogation if permissibility is still pairwise and monistic.Weight pluralism (justifying vs. requiring)
An alternative is Weight Pluralism: reasons have at least two distinct weights—justifying and requiring. On the Pluralist Pairwise view, φ is permissible iff φ's justifying weight is not outweighed by rivals' requiring weight. This promises stable, ubiquitous options and a tidy explanation of permissible partiality and supererogation.Some pluralists rank betterness among permissible options by requiring weight, while others posit a third, "favoring/merit-conferring/erogatory" dimension to handle "ought-as-best."
Supererogation and "ought as best"
On one usage, ought tracks the best permissible option, not merely the required one; this separates ranking from permissibility and helps locate supererogation. Competing proposals ground this ranking in requiring weight or in a distinct favoring/merit dimension.Exclusionary and higher-order reasons
Beyond first-order weighing, some defend exclusionary reasons—higher-order reasons not to act for certain first-order reasons. Critics worry this divorces "all-things-considered" action from the first-order balance, but defenders argue such reasons structure rational deliberation in law and practical life.In epistemology, some interpret certain higher-order evidence as excluding one's first-order evidence from justifying belief even if it remains evidence in a purely evidential sense.