Some Of Our Books


« Supervenience, Properties, and Relations | Main | There are unknowable moral truths »

August 08, 2010


Feed You can follow this conversation by subscribing to the comment feed for this post.

"But the circumstances of the world are such that S is metaphysically precluded from performing (A&B), so she cannot (A&B). Hence, it is both true that S ought (A&B) and false that S ought (A&B)."

I think this is a common misreading of the deontic principle. Suppose you take obligation to be closed under conjunction. In general, moral dilemmas won't show that the closure principle is faulty, since semantically O(A & B) amounts to no more than the claim that in all morally ideal worlds A & B is true. Since there is such a world, it is possible that A & B. There is no worry for ought-can. The worry, of course, is that we are not in a morally ideal world and (probably) don't believe that what we ought to do in sub-ideal worlds is anything like what we ought to do in ideal worlds. In other words, the moral principle you're assuming--say it's some form of utilitarianism--won't have the logic described in standard deontic logics unless it is an odd form of ideal utilitarianism. If it is that form of utilitarianism, you cannot generate a moral dilemma (well, almost can't). If you can generate a moral dilemma, then you've got the wrong logic.

A couple of options: both the applomeration principle (O(A) and O(B) entail O(A&B)) and OIC are questionable. My own probabilistic semantics for 'ought' invalidates agglomeration, for example (although this doesn't explain why it wouldn't hold in the case of DUTIES). And there's a good case to make that 'ought' only pragmatically implies 'can' (Sinnott-Armstrong 1984): if you're trying to guide somebody, it's not very helpful to consider impossible courses of action.

This might be an overly simplistic way of responding to the problem(s) you pose, but I take the central one to be about the nature of OIC. Maybe you can duck the dilemma by noting the commonality between the two options-(A:I [morally] ought to save the toddler and B: I [morally] ought to stay with grandma) is that they are both MORAL oughts (as opposed to other oughts, like 'I ought to save for retirement'). If the OIC principle was a general principle, why can't you say that for situations where you have OughtA and OughtB, and both of them are moral oughts, that the real point of the principle is that you have OughtMORAL, and you fulfill your obligation (or act morally, or whatever the language must be) so long as you do ANYTHING that is a current moral ought? If you A, you've fulfilled your moral obligation, but you can also fulfill is by B-ing. You can't do both, by stipulation, but (either) one is enough to fulfill the general OIC principle.

I guess, in a way, this is to deny this principle: (O(A) and O(B) entail O(A&B)) and replace it with (O(A) and O(B) entail O (A v B)). The open-endedness of the principle allows the second half of the equation to be replaced by anything in universe of 'moral oughts'. I admit, it would be weird to claim that someone who failed to both A (save the toddler) and B (keep Grandma safe) because they suddenly decided to do C (help with Haitian earthquake relief) was acting well, but I think that's the devil in the details about what makes a moral ought an 'active' ought at a particular time. I don't think a theory would be unreasonable to give priority to time-sensitive moral oughts (like A and B) over less time-sensitive ones (like C).

I think Steve and Eric are on the right track regarding the source of the problem, which is the principle: O(A) and O(B) implies O(A&B).

Consider an analogy: It is possible for me to turn right at the next intersection and it is possible for me to turn left at the next intersection. This does not imply that it is possible for to turn both left and right and the next intersection. In other words, "1. P(L); 2. P(R)" does not imply "3. P(L&R)", but rather only implies "3. P(L) & P(R)."

I think something like this is going on in the moral dilemma case.

Consider an analogy: It is possible for me to turn right at the next intersection and it is possible for me to turn left at the next intersection. This does not imply that it is possible for to turn both left and right and the next intersection

That's wrongly assimilating deontic obligation to alethic possibility. Deontic obligation is the counterpart of alethic necessity. Deontic permissibility is the analogue of alethic possibilty. Agglomeration does not hold for permissibility for the reasons you cite.

Thanks everyone for the comments.

Mike, I can see the force of moving to a possible world semantics for 'Ought', but as you note, this seems orthogonal to the anxieties many moral theorists have about the possibility of genuine dilemmas. That there is some world in which S can (A&B) hardly seems an argument that answers to worries about action guidingness, consistency, etc. in this world.

Eric and Steve both want to deny agglomeration: Eric opts for a disjunctive 'ought' or disjunctive obligation. Eric, I'd be curious to know how that disjunction would play out in terms of the sorts of concerns I raised in my post: blameworthiness, reactive attitudes, etc. My own sense is that in fulfilling a disjunctive obligation, I'd still be rightly subject to criticism, etc. for 'the road not taken,' so to speak, in a way that I'm not in standard applications of OIC where I couldn't have (categorically) done otherwise. What do you think?

Steve: Remind me again why your semantics doesn't yield the denial of OIC in the case of duties. I'm interested because the OIC argument meant to show the impossibility of genuine dilemmas could simply be recast in terms of 'Obligation implies can,' with standard OIC omitted. Is that right?


I was saying that while my semantics explains the invalidity of agglomeration, this doesn't extend to duties (the point being that duties can also be expressed with "must", being a matter of deontic necessity). But I was providing it only as an example; there may be other reasons why agglomeration fails for duties. (Suppose, for example, that we define duties as things that we owe to specific persons. It wouldn't follow from the fact that we owe A to a specific person and that we owe B to a specific person that we owe A and B to a specific person).

I wasn't linking my semantics with OIC at all. But I think the same argument that ought implies can only conversationally also extends easily to 'must implies can only conversationally'. The typical purpose of telling somebody what they ought/have to do is to influence their behaviour, so it is pointless to tell them they ought/have to do something impossible.


I think it is true that there is some sense that my disjunctive obligation argument still leaves a moral agent open to some form of moral criticism, but the way I was trying to cast it should make a milder form of moral criticism than "you failed to fulfill your moral obligation". The agent who A's (or B's) HAS fulfilled a moral obligation. In an ideal world, he would be able to do both A and B, but in this (real) world, he can't do both, so he does (morally) right by doing at least one thing he's morally obliged to do (either A or B).

If there is a sense in which he can be morally critiqued ("you should have helped that child!" or "you should have stayed with grandma!"), it seems to me that it can't be a serious, sustained critique without expecting someone to be able to do the impossible. At best, the critique can only be something like "Would that you could have helped the child" and nothing more stringent.

I'm assuming that there is no available lexical ranking or prioritizing of the moral obligations; A and B are equal in all of the relevant senses.

I think this disjunctive explanation also helps brush off some Singer-like arguments about samaritan duties. I may have an obligation to help the distant needy, but so long as I am fulfilling other moral obligations, I have not acted badly. Again, though, this only works when the moral obligations are equal-if helping the distant needy is lexical more important than, say, being a coach for my child's soccer team, I could be duly criticized for failing to help the needy. But that would require, at minimum, at least an argument supporting the lexical ordering.

I guess, to summarize my rambling, that the disjunctive explanation takes some of the sting out of the moral dilemma. I think it allows the dilemmas to be considered 'real' without seriously condemning someone for having to make a choice.

Mike Almeida,

Thanks, that's helpful. It seems to me that the problem that Michael Cholbi is concerned with arises just in virtue of this commonly assumed disanalogy between possibility and obligation. If O(A), O(B), implies O(A&B), and P(A), P(B), does not imply P(A&B) (where P is the modal operator for possibility, because I don't know how to render a diamond in a comment), and if we understand "ought implies can" to mean O(x)->P(x), then "ought implies can" is expressly connecting possibility with obligation.

One solution is to deny the deontic principle that O(A) and O(B) implies O(A&B). I think that there is a way of making sense of this, at least with imperfect duties, more or less in the way that Eric does. So, even if performing A does satisfy some moral obligation, and performing B does satisfy some moral obligation, it is not the case that I have an obligation to satisfy all instances of my imperfect obligations at the same time. For Kant, I think, what I have is an obligation to ensure that all of my actions satisfy some imperfect obligation or other, within the constraints of my perfect duties.

A different solution is to question this version of "ought implies can." Kant doesn't construe this principle as a matter of physical possibility, but rather as having to do with motivation. I think that construing it as a matter of physical possibility make the principle implausible. For instance, I have an obligation not to damage others' rightful property (this may be the source of their claim to damages if I do cause harm). I have this obligation even when I am driving and I lose control of my car, even when I have driven well within reasonable constraints. Still, if I run into your fence through no fault of my own (at least so long as it not someone else's fault) I can rightfully be made to recoup your loss, because of my obligation not to damage your rightful property. So even when it is not physically possible for me to avoid violating my obligation, I take it is plausible that the obligation remains in force. If that is right, then the principle O(x)->P(x) is not a good one.

if we understand "ought implies can" to mean O(x)->P(x), then "ought implies can" is expressly connecting possibility with obligation.


Ought-can, as it is used in deontic contexts (I mean, standard deontic contexts) just tells us that our obligations are consistent. This is perfectly analogous to the alethic modal case were (certainly) Nec P & Nec q -> Pos (p & q). So, combining moral necessity (deontic obligation) with alethic possibility does not generate the problem you cite. Or else, I don't see it.

One neglected feature of rejecting this or that theorem in SDL is that it can remove the inconsistency without accommodating moral dilemmas. Suppose you decide to reject agglomeration. This is pretty easily done using minimal models. But doing so semantically models someone who endorses two moral standards with two sets of ideal worlds. That can get you OA and O~A consistently, but it does not model a moral dilemma. All that tells you is that, relative to one standard, OA, and relative to another O~A. It tells you nothing about what you ought to do "all in". Genuine moral dilemmas have agents facing situations in which they are all-in obligated to do A and all in obligated to do ~A. It's really hard to model that situation properly. I'm not sure it can be done.

The comments to this entry are closed.

Ethics at PEA Soup

PPE at PEA Soup

Like PEA Soup

Search PEA Soup


  • Unless otherwise indicated, the views expressed in any given post reflect the opinion of only that individual who posted the particular entry or comment.