Skip to main content

Practical Reason


Reason can and should guide one in deciding what to believe, at least in large part. But can reason also guide one's actions and the goals that one aims to achieve through them? This question is at the heart of philosophical interest in practical reason. One's thoughts and discourse about practical matters are full of references to reason, and each day brings with it a fresh round of deliberation over such things as the costs and benefits of alternative lines of conduct. Disagreement over how best to understand these phenomena has focused on two distinct questions: First, is reason itself ever a genuine source of considerations for or against conduct, or is our everyday thought and discourse simply a façon de parler ? Second, to what extent, if at all, can such considerations make a difference to what one does? Under the first question, which is address in the first three sections of this entry, the central issues concern whether and the extent to which the deliberative process that culminates in a decision or intention can be dubbed reasoning. The second question, with which the article ends, concerns the nature of motivation and action and, in particular, what role (if any) reason plays in the explanation of one's behavior.

Instrumental Practical Reason

Most agree that if any conduct is contrary to reason, then not acting to achieve one's goals with some level of efficiency and effectiveness is. Once one decides to lose weight, for instance, overeating seems unreasonable. But what precisely is reason's role here? Many, such as those who follow the eighteenth-century Scottish philosopher David Hume, argue that its role is limited to delivering and evaluating beliefs about connections between behaving in certain ways and achieving goals. If one's goal is to lose weight, reason's work is done once it delivers the news that eating less will bring that about. This implies that reason concerns itself only with delivering causal information about how to realize one's goals and hence does work in the realm of action that is no different from the work it does in the realm of belief.

To see precisely how little reason does on such a view, consider the following: Suppose my goal is to have the doorbell to ring and I am told to push the button. However, I perversely insist that it is a trick door and that standing motionless will make it ring. If I stand motionless, I will as a consequence frustrate my goal. Reason seems against my conduct. For the minimalist, however, that means only that the belief on which my conduct was based was false. Suppose, alternatively, that I have no idea how to make a doorbell ring. I stand in puzzled silence, and again reason fails to support my behavior. This time, the problem is not that I have incorrect beliefs about how to achieve my goal; it is that I have no beliefs about this at all. Nevertheless, it is again really just in lacking a belief that I've fallen foul of reason. Conforming to practical reason, on this minimalist view, means simply ensuring that I have the right stock of beliefs about how to achieve my ends. Reason does not pass judgment on what I do per se. It is thus not practical in this more interesting sense. Indeed, when I do what I falsely believe will bring results, my action displays a kind of fit with my belief, even if my belief is itself defective.

Suppose, however, that my actions did not display this kind of fit with my beliefs, even while my beliefs were flawless. Imagine, for instance, I failed to push the button when my goal was that the doorbell ring and I correctly believed that pushing the button would achieve this. Was my conduct then contrary to reason insofar as it did not fit with my goal and my true meansends belief? A minimalist such as Hume would deny that it was. An action itself cannot be contrary to reason because an action cannot be evaluated for its truth or falsity. A fortiori reason cannot justify an action either, for justification of something is just support for its truth. Thus, no action seems contrary to reason in the way that a false or unjustified belief is.

Reason will be practical in an interesting sense, it seems, only if one of two things is true: Either there exists some special realm of facts about the to-be-doneness of certain actions themselves, information about which reason can deliver, or else reason is more than an information-delivering faculty. Philosophers have tended to avoid views requiring special facts although in the case of ethical reasoning, some have thought the idea worth developing. This case will be returned to below. For many, a more attractive strategy is to argue that reason issues distinctive rules of conduct. The most likely candidate for such a rule would be a rule of instrumental reason, for instance: Do what is necessary to achieve your goals. For an action to be contrary to reason would then be for it to fail to conform to such a rule. The key issue, then, is whether practical reason is indeed normative in this sense, that is, whether there are any genuine rules of reason.

Arguments that a given rule is a norm of reason can be grouped into two kinds: those appealing to the concept of reasonableness, and those appealing to substantive considerations beyond that concept. The eighteenth-century Prussian philosopher Immanuel Kant, for instance, employed the first style of argument regarding conformity to a hypothetical imperative. The concept of reasonable behavior, he argued, contains the idea of conformity to the rule take the means necessary to achieve your goals. The twentieth-century political philosopher John Rawls is an example of a philosopher who also employed the second style of argument. Rawls argued that reasonableness includes a willingness to propose and abide by fair terms of cooperation if assured that others will likewise do so, on the grounds that, although it is not a conceptual truth, the contention enjoys much intuitive support.

Reasoning about Goals

Goals can share many of the above features of actions. Suppose, again, my goal is that the doorbell ring. Typically, I don't just want that. Perhaps I believe that the ring will bring my friend to the door. My goal is really an instrumental goal, a goal that is desirable because its achievement is instrumental to achieving a further distinct goal. Suppose, however, that I am standing in front of the wrong house. Even though I am right to believe that pushing the button will achieve the ring, reason is against my pushing the button because it is against achieving the ring. To this instrumental extent at least, our goals can be contrary to reason.

Minimalists will be led say about goals mutatis mutandis what they say about action: The defect, as in the case of action, is in the belief that the ring will bring my friend to the door. It is only because of this false belief that my goal falls foul of reason. Goals are just like actions in the sense that they cannot be evaluated as true or false, and a fortiori cannot be justified or unjustified either. So, if reason were practical in any interesting sense, there would either have to be a distinctive realm of facts about the to-be-pursuedness of certain goals or else reason would have to issue distinctive norms concerning goals such as pursue intermediate goals necessary to reach your primary goals.

This sort of reasoning need not exhaust practical reasoning about ends. For instance, suppose I have not one, but two goals: that the doorbell ring and that those behind the door not be disturbed. Do I conform to reason if I push, or rather fail to push, the button? Given the bell cannot ring and leave the inhabitants undisturbed, the answer must wait until I resolve this conflict. Having goals that are not jointly realizable seems contrary to reason. However, goals are jointly realizable only if some can be dropped in favor of others in cases of conflict. We could do this willy-nilly, of course. But ranking seems more reasonable. We should decide whether having the doorbell ring is more or less important than disturbing those behind the door. Given reason counsels joint realizability, it thus also counsels ranking. Moreover, rankings conform to requirements of consistency. For instance, they are transitive: If ringing is ranked above not disturbing the inhabitants, and not disturbing them above not wearing out the button very slightly, then ringing should be ranked above not wearing out the button. This would explain why we would think it unreasonable for me to worry about wearing out the button given that I'm not worried about the more important fact that it will disturb them.

Presumably, one does not pursue all of one's goals for the sake of other goals, however. Some things one cares about for their own sakes; they are final goals. Can reason evaluate such final goals? One way that it might is this (Schmidtz 1995): Suppose I am a philistine, but then decide to become the sort of person for whom art is a final end. Suppose further that I decide this because I believe that becoming that sort of person will enhance my standing in the eyes of others. I aim, in other words, to come to pursue something for its own sake, but my reasoning is clearly instrumental. If I find out that learning to love art for arts sake will not lead others to think better of me, then reason will counsel me not to learn that.

Reason in Ethical Deliberation

When one deliberates about what to do, one often considers whether what one proposes is morally permissible, right, virtuous, and so on. One seems to care about such things for their own sakes, so this seems to constitute a final end. But does reason ever really guide one to moral conclusions?

Those who think that it does can be divided into two camps: those who think that moral reasoning can be explained in terms of reasoning from individual goals, and those who think it involves a special kind of reasoning. The former think that moral reasoning is, in fact, not fundamentally different from the above forms of practical reasoning but in some way facilitates the achievement of one's goalstypically, by being based on principles of social conduct that reasonable individuals would accept and act on. Such, for instance, is found in game-theoretic explanations of morality. On a standard version, game theorists argue that people seeking to achieve their goals will want ground rules for their interactions with each other. They will thus freely engage in a series of bargains with others in which each person tries to secure practices most favorable to their goals. Bargaining would continue until no viable alternative agreement can be struck under which someone would be better off. Moral practices represent these agreements, and because they do, they are justified in light of their being the upshot of these reasonable goal-oriented bargains. Along these lines, David Gauthier (1986) argues that reasonable agents will be disposed to cooperate with others who likewise cooperate, even when doing so will not be the best way to achieve their own goals (as is often the case in moral matters).

A more controversial idea is that moral reasoning is fundamentally different from nonmoral reasoning. There are two main lines of thought here: The first is that there is a distinct realm of moral facts, as real as any scientific fact but accessible only through the exercise of a special faculty of reason. On this view, practical reason operates quasi-perceptually to deliver putative moral facts such as that lying is wrong. Some (McDowell 1979) have held that this is analogous to sense perception, such as is exercised by informed palates when they perceive differences between wines. Others (Ross 1939) think of it as more akin to intellectual perception, such as is exercised in the perception of mathematical truths. Many, however, find this postulation of a sui generis faculty of reason too mysterious to accept.

The second line of thought does not appeal to the exercise of a special faculty and access to special facts but to a special rule distinct from those connected to advancing individual goals. The most famous attempt to defend this line of thinking comes from Kant. Moral reasoning is based, he argued, on a rule he referred to as the Categorical Imperative. This rule requires one not to act in ways that one could not want everyone else also to act. Every rational agent is committed to this rule, Kant argued, simply by engaging in practical reasoning. Committing oneself to this rule is a presupposition of taking up the point of view of practical deliberation. Therefore, he concluded, it is a rule of practical reason. Few have found Kant's arguments convincing. Nevertheless, some contemporary philosophers have tried to develop and defend some version of Kant's ideas. Rawls's idea of reasonableness is one attempt. Another is Thomas Scanlon (1998) who argues that reasonableness requires being responsive to the appropriateness of principles of conduct to serve as foundations for mutual recognition and accommodation.

Reason and Motivation

Suppose deliberating to conclusions about what to do is genuinely a form of reasoning. These conclusions may still make no difference to what one does. Reason, that is, may not be practical in another sensein the sense that it cannot motivate one to comply with its conclusions. When one acts contrary to conclusions of practical deliberation, is one unreasonable in the sense of being insufficiently motivated by this deliberation?

Internalists about practical reason hold that one can be: The conclusions of practical reasoning must motivate reasonable agents. This is especially the case, they argue, in moral reasoning: It is not possible to believe it to be wrong to lie, for instance, yet remain unmotivated to tell the truth. One reason internalism is attractive is that it explains the magnetism conclusions of practical reasoning exhibit. To be sure, the conclusions of practical reasoning do not always motivate everyone. If one is depressed or weak-willed, for instance, practical conclusions may have no motivational effect on one. So, internalists must stipulate which psychological condition a reasonable agent is in such that that agent must be motivated. This has not proven to be an easy task.

Internalism, however, appears inconsistent with an attractive conception of motivation, often referred to as the Humean view. On this view, motivation requires, in addition to belief, a desire. Michael Smith (1995) has offered an influential defense of this view. Briefly, the leading idea is that the best functional account of belief and desire gives them different directions of fit with the world. A belief is an attitude toward a given proposition p, such that the perception of not-p disposes the believer to change attitude to not-p. Desire has the reverse direction of fit: an attitude toward p such that the perception of not-p disposes the desirer to change the world to p. If these accounts are basically right, then three things seem clear: Motivation requires a desire, beliefs and desires are only contingently related, and no state could have both directions of fit. Smith himself argues that, nonetheless, one's beliefs about what one has reason to do must motivate agents in the right psychological condition. His position is controversial, however, and the prospects for internalism remain unclear.

See also Decision Theory; Game Theory; Hume, David; Kant, Immanuel; Normativity; Rationalism in Ethics (Practical Reason Approaches); Rawls, John; Reason.


Blackburn, Simon. Ruling Passions. Oxford: Clarendon, 1998.

Bratman, Michael. Intention, Plans, and Practical Reason. Cambridge, MA: Harvard University Press, 1987.

Broome, John. "Normative Practical Reasoning." 175193. Aristotelian Society: Supplementary Volume. 2001.

Dancy, Jonathan. Moral Reasons. Oxford: Basil Blackwell, 1993.

Darwall, Stephen. Impartial Reason. Ithaca, NY: Cornell University Press, 1983.

Gauthier, David. Morals by Agreement. Oxford: Oxford University Press, 1986.

Gibbard, Alan. Wise Choices, Apt Feelings. Cambridge, MA: Harvard University Press, 1992.

Hill, Thomas E., Jr. Dignity and Practical Reason. Ithaca, NY: Cornell University Press, 1992.

Hume, David. A Treatise of Human Nature, edited by D. F. Norton and M. Norton. New Ed. Oxford: Oxford University Press, 2000.

Kant, Immanuel. Groundwork of the Metaphysics of Morals, edited by A. Zweig and T. E. Hill, Jr. Translated by A. Zweig. Oxford: Oxford University Press, 2002.

Korsgaard, Christine. "The Normativity of Instrumental Reason." In Ethics and Practical Reason, edited by Garrett Cullity and Berys Gaut. Oxford: Oxford University Press, 1997.

Korsgaard, Christine. "Skepticism about Practical Reason." Journal of Philosophy (1986): 525.

McDowell, John. "Are Moral Requirements Hypothetical Imperatives?" Aristotelian Society Supplementary Volume (1978): 1329.

McDowell, John. "Virtue and Reason." Monist 62 (1979): 33150.

Nagel, Thomas. The Possibility of Altruism. Princeton, NJ: Princeton University Press, 1978.

Parfit, Derek. Reasons and Persons. Oxford: Clarendon Press, 1984.

Rawls, John. "Kantian Constructivism in Moral Theory." Journal of Philosophy 77 (1980): 515572.

Rawls, John. A Theory of Justice. Cambridge, MA: Harvard University Press, 1972.

Raz, Joseph. Practical Reason and Norms. Oxford: Oxford University Press, 1975.

Ross, W. D. Foundations of Ethics. Oxford: Clarendon Press, 1939.

Scanlon, Thomas. What We Owe to Each Other. Cambridge, MA: Harvard University Press, 1998.

Schmidtz, D. Rational Choice and Moral Agency. Princeton, NJ: Princeton University Press, 1995.

Smith, Michael. The Moral Problem. New York: Routledge, 1995.

Stocker, Michael. "Desiring the Bad: An Essay in Moral Psychology." Journal of Philosophy 76 (1979): 73853.

Velleman, David. "The Possibility of Practical Reason." Ethics 106, No. 4 (1996): 694726.

Wallace, R. Jay. "How to Argue About Practical Reason." Mind 99 (395) (1990): 355385.

Wallace, R. Jay. "Normativity, Commitment, and Instrumental Reason." Philosopher's Imprint. 1 (3) (2001): 126,

Wiggins, David. "Deliberation and Practical Reason." In Essays on Aristotle's Ethics, edited by A. O. Rorty. Berkeley: University of California Press, 1980.

Williams, Bernard. "Internal and External Reasons." In Moral Luck: Philosophical Papers, 19731980. Cambridge, U.K.: Cambridge University Press, 1981.

Robert N. Johnson (2005)

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Practical Reason." Encyclopedia of Philosophy. . 15 Aug. 2018 <>.

"Practical Reason." Encyclopedia of Philosophy. . (August 15, 2018).

"Practical Reason." Encyclopedia of Philosophy. . Retrieved August 15, 2018 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.