When H.A. Prichard launched his attack on the “mistake” in moral philosophy of “supposing the possibility of proving what can only be apprehended directly by an act of moral thinking,” he had Plato squarely in his sights. I Plato, in fact, is the poster boy for the strategy of trying to “supply by a process of reflection a proof of the truth of what … they have prior to reflection believed immediately or without proof.” As if this were not mistake enough, Prichard charges Plato with being the “most significant instance” of the error of trying to “justify morality by its profitableness,” because Plato's general acuity brings into sharp relief just how pernicious is the temptation to offer such justifications. Prichard has in view Plato's attempt in Republic to demonstrate that justice is oikeion agathon - one's own good - and Prichard complains that at best such an account can make us want to be just, rather than show us that we are obligated to be just, as direct apprehension purports to do.

H.A. Prichard famously argued that philosophers who aim to answer the question “why are we bound, or why ought we, to do what is right?” are pursuing a vain quest. Prichard advertized this finding in a provocative way, asserting that moral philosophy is the mistaken enterprise of trying to reply to a question to which no replies are possible. Should we be skeptical about the resources of philosophy for addressing issues about morality's authority? In my view, Prichard was mistaken. But identifying his error requires getting clear about how reasons of autonomy contribute to a person's normative reasons for action.

Morality teaches us that, if we look on her only as good for something else, we never in that case have seen her at all. She says that she is an end to be desired for her own sake, and not as a means to something beyond. Degrade her, and she disappears. - F. H. Bradley

Morality can be painfully demanding, so much so that we sometimes question the wisdom of complying with it. Yet, arguments that we have good reason to be moral are as old as Plato's Republic. Indeed, according to H. A. Prichard, making this argument work is the central preoccupation of moral philosophy. But Prichard also believes that, to the extent this is true, the whole subject of moral philosophy rests on a mistake.

A person who sees that she morally ought to do something might wonder whether it would make sense for her to do it. Perhaps Aurelia is on a crowded bus, standing next to an old man whose wallet is almost falling out of his pocket. She says, “I see that the morally right thing would be to warn this man to take care of his wallet. But why should I do the right thing? In fact, why shouldn't I steal his wallet? It would be wrong of me to do this, but so what? No one is looking. I won't get caught. What's to fear?“

We can imagine different scenarios of this kind. In one scenario, Aurelia is on the verge of deciding to steal the old man's wallet. She believes it would be wrong to do this, and she is asking whether there is any (further) reason not to go ahead.

Although many associate the terms with Bernard Williams’ work on practical reason, the terms ‘intemalism’ and ‘externalism,’ along with the general contours of debates in ethical theory between views so dubbed, were originally introduced by W.O. Falk in a response to H.A. Prichard's intuitionist account of ‘ought.’

H.A. Prichard's “Does Moral Philosophy Rest on a Mistake?”, like Descartes Meditations, is remembered better for the skeptical moment in the author's thinking than for its unskeptical conclusions. Prichard's paper is complicated, but the lore about its message is simple. The lore is that Prichard pointed out that in trying to vindicate the reason-giving power of morality we might do so by appealing to moral norms or to non-moral norms. If we appeal to moral norms, then we are only justifying a standard in terms of that standard and just about any old standard could survive such a test.

The question “Why be moral?” is open to at least three extremely different interpretations. One way to distinguish these interpretations is by picturing the question as being asked by, respectively, Allan, who is going to act immorally unless he can be convinced to act otherwise, Beth, who is perfectly happy to do what is morally required on a certain occasion but who wants to know what is it about the act that makes it morally required, and Charles, who is trying to understand why rational people act morally. An answer to the question as understood by Allan is, for some, the holy grail of moral philosophy, and it is also perhaps the default understanding of the question. The question as asked by Beth is what David Copp, in his contribution to this volume, calls the “why-think-morality-requires-this” question. The question as asked by Charles can be called the “what-rationally-justifies-moral-behaviour” question. Charles’ question, importantly, is about rational permissibility, and it is most pointed when moral behaviour requires sacrifice.

The power of skepticism depends on the apparent possibility of rationally asking, for virtually any kind of proposition commonly thought to be known, how it is known or what justifies believing it. Moral claims are among those commonly subjected to skeptical challenges and doubts, even on the part of some people who are not skeptical about ordinary claims regarding the external world. There may be even more skepticism about the possibility of justifying moral actions, particularly if they are against the agent's self-interest. Both problems-how to justify moral claims and how to justify moral action - come within the scope of the troubling question “Why be moral?” Even a brief response to moral skepticism should consider both kinds of targets of justification, cognitive and behavioural, and should indicate some important relations between the two types of skeptical challenge. I will begin with the cognitive case- with skepticism about the scope of theoretical reason in ethics - proceed to practical skepticism, which concerns the scope of practical reason, and then show how an adequate account of rationality may enable us to respond to moral skepticism.

The question “Why be moral?” has been on philosophers’ agendas at least since Plato, and the antiquity of the Question (which is what I'll call it from here on out) reasonably prompts the suspicion that moral skepticism may not in the end be rebuttable. Haven't we waited long enough? Isn't it time to discard the pretense that we have reason to do what morality demands? And shouldn't we finally stop wasting our time on it?

Before buying into that conclusion, I want to point out a largely untapped source of reasons for being moral. It has been overlooked, I will suggest, in part because attention has been exclusively directed to providing a definitive refutation of moral skepticism. However, that fixation is attributable to a very basic error about what sort of creatures we are. Most of our reasons come with expiration dates; and, indeed, the Question is often answerable, but temporarily rather than definitively.