In “Internal and External Reasons,” Bernard Williams presents an argument for thinking that external reasons do not exist, and thus all external reasons statements are false. In this paper I will do three things. First, I will explain what Williams understands internal reasons and external reasons to be. I will then explain Williams’ argument against external reasons. Finally, I will attempt to give some defense of external reasons by critiquing Williams’ argument.
The general form of a reasons statement is “A has reason to do F in circumstances C.” Williams aims to show that statements of this form are only ever true on an internal interpretation. While Williams does not seem to give a definition of internal reasons statements, he does lay out what seems to be a necessary condition on internal reasons statements. He says that any internal interpretation of a reasons statement must “display a relativity of the reason statement to the agent’s subjective motivational set,” which we shall call “S.” Roughly then, internal reasons for an agent are dependent on what is in the agent’s subjective motivational set.
Williams also lays down as a necessary condition on internal reasons that they can be discovered by deliberative/practical reasoning. While Williams does not explicitly define what deliberative or practical reasoning is, he specifies his conception of deliberative/practical reasoning via example. In particular, he says that practical reasoning includes means/end reasoning about the most preferable way of satisfying a desire, temporal ordering of when to satisfy which desires, determining which desires one is most interested in satisfying, and determining what would constitute satisfaction of one’s desires. So, this condition amounts to saying if A has an internal reason to F, A must be able to motivate herself to F by a process of reasoning of this sort (from S).
It is clear then that Williams is working with an idea of internal reasons that ties them closely to an agent’s current subjective motivational set. It is also clear that he is working with a “thin” notion of practical rationality. Since Williams doesn’t explicitly define what he takes rational deliberation to be, it is difficult to precisely state what this “thin-ness” amounts to. However, roughly speaking, Williams’ account of rationality is “thin” insofar as, on his view, a decision will count as rational to the extent that it could be concluded to by a process of deliberation starting from one’s desires and satisfying certain (relatively weak) formal constraints.
What about external reasons then? One thing that is clear is that if A has an external reason to F in C, then A has this reason independent of her motivational set S. On the other hand, Williams holds that all reasons for action must at least be possible explanations for actions, and this applies to external reasons too. While there is a lot more one might think about external reasons for action, these assumptions are enough to get Williams’ argument off the ground. Any externalist view of this sort will be susceptible to Williams’ argument.
Let us turn to Williams’ argument then. Williams’ argument has two parts. In the first part, Williams argues that external reasons cannot by themselves help explain anyone’s action.
· 1’. If R can be an external reason for action, then either R by itself can help explain A’s acting in O or R by itself cannot help explain A’s acting in O. [Premise]
· 2’. If R by itself can help explain A’s acting in O, then R by itself must be able to motivate A. [Premise]
· 3’. So if R can be an external reason for action, then either R by itself must be able to motivate A, or R by itself cannot help explain A’s acting in O. [1’, 2’ CD & HS]
· 4’. If R can be an external reason for action then R by itself cannot motivate A. [Premise]
· 5’. So, if R can be an external reason for action then R by itself cannot help explain A’s acting in O. [3’, 4’ DS & HS]
The first premise follows from the law of excluded middle. The second premise is Williams’ own view, namely that “nothing can explain an agent’s (intentional) actions except something that motivates him so to act.” The premise in line 4’ is meant to follow from the fact that if agents have external reasons they have them independent of their motivations.
Now, if the argument does in fact show that external reasons cannot by themselves explain an agent’s action, then any external reason statement will require some additional fact to help explain the agent’s action. Williams takes it that the externalist’s best bet is to appeal to an agent’s belief about what she judges herself to have reason to do. This leads to the second part of Williams’ argument, which shows that external reasons don’t exist.
On Williams’ view, in order for a belief to be able to explain an agent A’s action, when the belief is acquired it must also generate a motivation in A. Presumably Williams assumes this because he thinks beliefs by themselves cannot motivate, and can thus explain only via the explanatory power of any motivations they produce. Moreover, for a belief about external reasons to explain an agent A’s action, it must be that A acquires the motivation because of her belief. Finally, Williams assumes that, on an externalist view, if A correctly deliberates to the conclusion that she has external reason to do F, then A will come to believe she has external reason to do F.
All of this, Williams concludes, commits the externalist to thinking there is a necessary connection between external reasons and motivation. In particular, he thinks the externalist is committed to the premises of the following argument.
· 1. If A has external reason to F in C then if A were to rationally deliberate in C, then A would be motivated to F. [Premise]
· 2. Given that were A to rationally deliberate in C she would be motivated to F, then there is some motivation in S for A to deliberate to F from. [Premise]
· 3. So, if A has external reason to F in C, then there is some motivation in S for A to deliberate to F from. [3,4 HS]
· 4. But there is no motivation in S for A to deliberate to F from. [Premise]
· 5. So, A has no external reason to F in C. [3,4 MT]
Hence, any external reason statement must be false.
Premise 1 is meant to follow from Williams’ points mentioned above. Roughly: If correct deliberation implies belief in external reasons, and such belief implies motivation, then if one were deliberating perfectly one would be motivated to do what one has external reason to do. Premise 2 seem to follow from Williams’ understanding of rationality: Again, rational deliberation is to be characterized in the “thin” sense explained above, as obeying a certain set of formal constraints which are defined relative to one’s subjective motivational set S. Finally, I take 4 to follow from Williams’ understanding of what an external reason would be; it must be possible for an external reason statement to be true independent of a given agent's motivational set S.
As should be clear by now, Williams has laid out a rather complex argument against externalism. There are a number of places where the argument is open to potential objection (e.g., in the characterization of externalism, or in the first part of the argument). However, for the purposes of this paper I will only focus on the second part of Williams’ argument (i.e., 1 – 5, along with the paragraphs immediately before it). This is where I hope to critique his argument.
I think an externalist resisting this argument should question premise 1. Note that when Williams speaks of “rational deliberation” here, he has in mind the same “thin” sense of rationality and deliberation described above. On this view, very roughly, an action counts as rational to the extent that it best contributes to satisfying one’s desires and satisfies certain formal constraints.   This is why premise 2 is plausible: If perfectly rational deliberation would make one motivated to F, then there must be some current desire whereby one could “get” to F via perfectly rational deliberation. Let us call this sense of practical rationality “thin-rationality” or “t-rationality.”
However, if 1 is to be read according to this interpretation of rationality, then no externalist should accept it. For we could then re-phrase 1 as follows:
· 1*. If A has external reason to F in C then if A were to t-rationally deliberate in C, then A would be motivated to F. [Premise]
However, clearly externalists would not want to accept 1*. For one, once it is being made explicit that we have t-rationality in mind, there is no guarantee that mere t-rational deliberation will motivate one to do what one has external reason to do. I can have external reason to F even if I have a set of desires according to which I could not t-rationally deliberate to F from those desires.
Moreover, it seems that external reasons are not only supposed to exist independently of a particular agent’s desires; they are supposed to be independent of the desires of any agent in those circumstances. But it is plausible that even if some agents could become motivated to F by perfect t-rational deliberation, it doesn’t follow that any agent in those circumstances could. For instance, someone might start off with radically different and deviant desires than someone else. So, if 1 is read under this interpretation then 1 builds into the concept of ‘rationality’ something no externalist would accept, viz., that external reasons are grounded in current desires. Thus, no externalist should commit herself to 1; no externalist view could imply this.
Of course, the internalist has a reply to this: If t-rationality is the only viable interpretation of rationality, making this the only type of practical rationality there is, then the internalist could say, “So much the worse for the externalist.” For the externalist must be committed to some version of 1 in some sense of ‘rationality’, and if no such version is true then externalism is false.
Granting that there must be some interpretation of ‘rationality’ according to which 1 is true, the challenge for the externalist becomes that of producing some coherent “thick” conception of rationality that is (i) distinct from t-rationality, but is at the same time (ii) a genuine conception of rationality. Call this “Thick-rationality” or “T-rationality.” On such a conception of rationality, satisfying the formal constraints of t-rationality are not enough to make a decision rational. Rather, satisfaction of certain more substantive conditions (for instance about the contents of one’s desires) is also necessary for a decision to count as rational.
If there is some legitimate conception of rationality of this sort, the externalist can respond that, when read in light of t-rationality, premise 1 is not plausible, and no externalist should accept it. However, when read in light of T-rationality, premise 1 does become plausible. The argument gains its superficial plausibility then from an equivocation between t-rationality and T-rationality; the reason 1 seems plausible at first sight is because there is another, more “thick” understanding of practical rationality, according to which 1 is actually true. Of course, this opens up the question: What is this thick conception of rationality supposed to amount to, and is it coherent?
Before proceeding with some suggestions about how this might go, I want to make two points about the argument thus far. Consider the thesis that if A has reason to F, then if A is perfectly rational she will be motivated to F. This is usually taken to be an internalist constraint on what reasons for action are. But presumably what makes this a distinctively internalist constraint is that the understanding of rationality here is one which is responsive to internal reasons (of the sort Williams describes). Thus, insofar as this constraint is meant to rule out externalism, this will turn on the understanding of rationality here being suitably “thin.” But in that case the externalist could respond by saying that the constraint as stated is true so long as we have a suitably “thick” understanding of rationality, in which case the constraint won’t rule out externalism. Thus, crucially, the internalist must argue that there is no legitimate conception of rationality of this sort.
But then there are two points to note from this: First, the internalist is committed to there being no legitimate notion of rationality other than the thin one; i.e., the only legitimate conception of rationality is the “how-to-best-satisfy-my-desires” model. But one might worry that this is a rather broad and dogmatic claim – on the face of it not very obvious – which will require quite a bit of heavy argumentation (much more than Williams has given us). Second, in that case, the internalist constraint is not itself what is doing the work against externalism, but rather whatever objections an internalist might have to thick conceptions of rationality. But then any argument against externalism purportedly making use of this constraint is really no more (or less) forceful than whatever arguments internalists have against thick conceptions of rationality.
Let us turn to the thick conception of rationality then. While I will obviously not be able to supply a complete and thorough account of rationality here, I would like to do two things. First, I would like to offer some evidence for thinking there is at least some thick conception of rationality that is legitimate. Second, I would like to give some outline of what one such thick conception might look like. While this is certainly no decisive refutation of Williams, it does present a challenge, since I think the evidence I will offer regarding the first point is common-sensical and ubiquitous, and the challenge for Williams will be to show that any thick conception of rationality attempting to incorporate these facts is doomed. But then the outline of a seemingly coherent picture of thick rationality suggests otherwise. This will be enough to show that Williams’ work is cut out for him, and that much more needs to be said than he has said here.
First, (1) consider someone who continues to smoke three packs of cigarettes a day, even though she knows it is going to kill her. However, she really doesn’t care. It still seems there is a sense in which we would say, “That’s stupid of her.” In other words, to put it more nicely, it’s unreasonable. (2) Consider also someone who likes to count blades of grass all day, and who wouldn’t derive more pleasure from anything else (not that she derives a ton of pleasure in the first place). There still seems to be a sense in which this is an unreasonable way to live out one’s life. (3) Consider next a person who has decided, to make a philosophical point about the power of free will, that whenever he sees something he will lick it. Suppose free will is so dear to him that carrying this out matters more than anything else. Suppose eventually he gets so accustomed to this that after some time he forgets about the free will stuff and just has an extremely strong desire to lick things. Such a person still seems to exhibit irrational behavior. (4) Consider some murderer who concludes that it’s okay to abduct and torture children for fun. This seems quite an unreasonable conclusion. (5) Consider a principal who punishes students for missing school even when dangerously ill. This is unreasonable of her. (6) Finally, consider the following conversation: A: “You need to be nice to your wife; it’s the right thing to do.” B: “But I don’t want to and I don’t care!” A: “That doesn’t matter; you should be nice.” B: “Oh yeah? Why should I?” M: “Because it’s the right thing to do.” This conversation strikes us as felicitous.
This all seems right. But none of these reasons statements are clearly true when read internally, given a “thin” interpretation of rationality (and the cases could probably be modified to make this even more obvious). Of course, if the argument given by Williams goes through, they are either false or are actually internal statements. But as we’ve seen, Williams’ argument is plausible only insofar as he has some additional argument for the incoherence of any thick conception of rationality. And in the absence of that additional argumentation, the most straightforward way to read these reasons statements is (a) externally, (b) relative to a non-thin (i.e., thick) conception of rationality, and (c) as true. This is the prima facie evidence for thinking there is at least some legitimate sense of rationality which is “thick” rather than “thin.” For it seems that we judge the actions and even desires of these people to be contrary to reason, even if they cohere well with their actual subjective motivational set.
Now I’d like to outline a possible account of what thick rationality consists in. While this will be incomplete and imperfect, the fact that it is not obviously wrong seems to give us at least some reason for thinking that something in this direction could work. First, let’s clarify the notion of reasons for action. A reason for performing F in circumstance C is some state of affairs or consideration that could make performing F in C practically intelligible. This is why reasons for action can rationally explain one’s action. Let me illustrate what I have in mind via example.
If you found me in a chair stabbing myself in the leg, you might ask me why I’m doing what I’m doing. “Does your leg hurt? Is someone sadistically paying you to do this? Is this how your tribe mourns the loss of loved ones? … ” Suppose to all such questions I responded, “No, I just desire to stab myself.” This wouldn’t really answer your question. There is still a clear sense in which what I’m doing is unintelligible, and wouldn’t make sense even if I obeyed some bizarre psychological laws which led me to “just desire” to stab myself in the leg. If however I said, “I am scared there is a tiny alien in my leg, and I need to get it out so it doesn’t kill me,” I will at least have described some state of affairs where, when my action is seen in light of this, my action does at least become intelligible (even if, in all likelihood, it is still utterly ridiculous and unreasonable). Such a state of affairs is a reason for acting a certain way; it can explain my action by making it intelligible.
If this is how we understand reasons for action though, then it is not at all obvious that the only type of thing that can be a reason for action is something suitably related to one’s subjective motivational set. For on this account, R is a reason for doing F in C just in case for some agent A, if A does F in C because of R, then A’s doing F is intelligible. But it seems there are lots of things that could make someone’s action intelligible that aren’t necessarily related by t-rationality to my current desires. Doing things because they foster one’s health makes sense. Doing things because they contribute to building lasting friendships makes sense. Doing things because they help others to gain knowledge makes sense. Hence, these are reasons for action, and they are reasons for action whether anyone has an appropriate desire or not. Indeed, it seems that these things make our action intelligible insofar as they are things that are objectively good for us; and arguably whether something is objectively good for us is independent of our desires and motivations.
The thick conception of rationality I have in mind then is one defined in terms of appropriate responses to reasons for action in this sense, and in this sense facts about what is objectively good for us seem to be capable of being reasons for action. Now, if facts about what is good for us are legitimate reasons for action, then being perfectly rational must consist at least partially in being motivated by what is objectively good for us. But it is not clear one can always be motivated by t-reasoning from one’s present desires to pursue what’s objectively good for oneself. So being perfectly rational cannot consist in t-rationality, and thus there must be some thick conception, T-rationality, which consists in appropriate responses to reasons for action. While I obviously don’t have a fully worked out theory of rationality here, it seems this provides a prima facie challenge to Williams. Insofar as we have reason to think a thick conception of rationality like this is coherent, Williams’ argument against external reasons doesn’t hold up.
 Technically, he argues that they are false, incoherent, or misleading (and thus should instead be rephrased as internal reasons statements). See the last paragraph of p. 297.
 This is found on p.292, bottom right paragraph.
 William does not explicitly list what is in this set, but roughly speaking it consists of an agent’s desires broadly understood. Examples include “dispositions of evaluation, patterns of emotional reaction, personal loyalties, and various projects …” He does however note explicitly that it does not include “needs.” Cf. p. 294, top right.
 On p. 293, bottom right.
 See p. 294, bottom right.
 “The whole point of external reason statements is that they can be true independently of the agent’s motivations.” See p. 295, top right.
 Cf. p. 295, top right.
 By “externalism” I of course mean the view that some external reasons statements are true.
 Or at least should. The text is a bit unclear on this I think. Williams uses the word “should,” but it’s not entirely clear to me whether it is meant to have any normative force or just denotes what would, in fact, happen according to externalism. I’m opting for the latter interpretation, though I think it probably isn’t essential.
 For all of this, see the bottom left of p. 296. It is a little bit difficult for me to see where Williams is getting all of his premises from, and again I think some of his statements are ambiguous between different interpretations of his use of “should,” but this seems to me the most charitable and straightforward interpretation of his argument.
 Or at least should imply. Again, I think the argument could be made to work on either interpretation of Williams.
 Again, Williams certainly wouldn’t give an explicit definition of rationality in this way. Williams is content to give a rough picture via examples. Similarly, I am only giving a rough picture, by characterizing rationality in a way that picks out something roughly similar to what Williams has in mind.
 By a “formal constraint” I mean, roughly, a constraint the spelling out of which does not require essential reference to the particular contents of one’s desires. For instance, “It is irrational to satisfy a weaker desire at the expense of a stronger desire when each is equally easy to satisfy.” While it may be false, this constraint counts as a purely “formal” constraint in the sense I’m concerned with.
 For some related discussion, see Michael Smith, The Moral Problem, pp. 164–174.
 See, e.g., Smith, “The Externalist Challenge.” Moreover, arguably, the only plausible internalist views will be ones which restrict the motivation to rational agents in a way like this, and so have constraints similar to this one.
 Again, this is a bit unfair because Williams wouldn’t put it so pithily, but this is indeed roughly the understanding of rationality Williams has in mind, and thus the only kind of rationality internalists can accept as legitimate.
 One might also begin to worry about how much normative significance practical rationality has if this is the only legitimate conception of rationality. Philippa Foot worries that if having the desire to torture children can be perfectly rational, then what’s so important about practical rationality in the first place? Why is practical rationality the most fundamental sense in which we can say we ought to do something? Why do we tend to give it the status of a “master virtue?” See Foot, Natural Goodness, pp. 62-63. One can take her argument further: If this is the only sense in which something can be rational, then practical rationality is not what ultimately normatively binds us at all; there will clearly have to be something else, some other more fundamental sense in which we “ought” to do certain things (which always rules out blatantly evil things, such as torturous desires).
 This account is largely adapted from G.E.M. Anscombe’s book Intention, sec. 37. Roughly, in Anscombe’s terms, a reason for action is some “desirability characterization,” i.e., some description which, when an action is intended under that description, makes the action seem “desirable,” “worth doing,” or “having a point.”
 And conversely, as we saw by our example above, the mere fact that someone desires something might not make it intelligible at all.