In general, philosophers take it for granted that a person morally ought to X if and only she can X. I'll treat this as equivalent to claiming that a person can have an all-things-considered moral duty to X if and only she can X. So, e.g, I cannot have an all-things-considered duty to shoot magic fireballs from my fingers because I am physically unable to do so.
Outside of ethics, though, there seem to be a few cases where intuitively we don't accept this, or, at least, I don't.
1. Consider norms of epistemic rationality: Suppose the evidence available to me strongly justifies belief in P–it is epistemically irrational not to assent to P in light of my evidence. If so, then I ought (epistemically) to believe that P. However, it's not clear in exactly what sense I can believe that P. Belief voluntarism is probably false (despite the existence of motivated reasoning), so let's assume here that I cannot just choose to believe that P. So, I cannot believe that P in the sense that I am unable to bring myself to do so, at least not immediately. (And I am rationally obligated, let's say, to believe that P right away, given how excellent my evidence is.)
Still, you might say that I am in some sense physically or psychologically capable of believing that P–it is not incompatible with some important or essential description of my psychology that I believe that P. My brain is capable of putting P in its belief box (though not by immediate voluntary assent). I just don't happen to have P in the box right now and cannot simply put it there by will.
However, suppose that I have some sort of neurological defect such that I become physically incapable of believing that P even in light of the evidence. I am otherwise a normal epistemic agent, but I just can't be made to believe that P, though I have overwhelming evidence that P. My belief box is broken and can't hold P in it anymore. Here, I'm still inclined to say that I epistemically ought to believe that P, though I can't believe that P. However, I'm inclined to add that my lack of belief in P is not obviously blameworthy. I violate norms of epistemic rationality–and the norms really do apply to me–but I am not blameworthy for doing so.
This is all tentative, but these are my starting intuitions with epistemic rationality. I'm a bit worried that it will be hard to maintain "ought implies can" with epistemic rationality without also having to accept some form of belief voluntarism.
2. Grammatical/Syntactical Oughts: There are norms about how to put sentences together. This first sentence is grammatical. Second this isn't sentence.
Suppose Agnes suffers a brain injury that prevents her from being able to form grammatical sentences. She retains an understanding of English semantics, but cannot abide by norms of syntax. So, when she wants to express an idea, she'll say the needed nouns, verbs, adjectives, prepositions, etc., but won't put them in the proper order. (Apparently, there are real cases of people having this problem after brain injury.) It still seems to me that Agnes ought to speak grammatically, though she can't. She violates norms of good grammar–and the norms really do apply to her speech–but she is not blameworthy for doing so.
If there's a difference between these two cases and moral cases, perhaps it's that in general, violations of moral oughts are blameworthy.
Hi Jason,
The view that I think is correct is that ‘ought’ implies ‘can’ only pragmatically, not analytically or metaphysically. See Walter Sinnott-Armstrong, “‘Ought’ Conversationally Implies ‘Can'”, Phil Review 93 (1984). Walter tells me that an earlier paper by Michael Stocker makes a similar case.
The basic idea is that since the normal purpose of telling people what they ought to do is to guide their actions, there isn’t any point in telling them they ought to do something they are unable to do. However, that holds only so long as the purpose of the conversation is indeed to guide actions.
I’m with you in the epistemic and the grammatical case, but that just leaves me puzzled about the moral case. It’s just hard to believe that people can be morally obligated to do that which they cannot do. To take your example, imagine you’re in a situation where it would be good (morally) to shoot magic fireballs from your fingers. It seems very odd to think that you ought to do so. It seems odd even if we revise the case to make it more like the epistemic and grammatical cases: most people can shoot magic fireballs, but your shooting mechanism is defective.
So I’m not sure what to conclude. In light of the epistemic and grammatical cases, should we conclude that the appearances in the moral cases are misleading? I would have a hard time justifying that asymmetry, but I find the claim that you ought to shoot fireballs out your fingers quite bizarre.
Interesting post. Here’s what someone might say about the two cases.
First, I’m with you that some form of doxastic involuntarism is true. This makes me think that, if in the first case, the evidence is available for you, then you cannot help yourself but to believe that P. I don’t think this calls into question ought implies can principle but rather an ought implies cannot principle. But that principle is probably not true in ethical contexts either.
The second part of the first case is more intriguing. I’m having difficulties in conceiving what the case could be like. The best one I could think of were the Japanese hold-outs after WWII. They could not just believe that Japan had lost the war. But, then there’s questions in what sense the evidence was available to them – after all, they reinterpreted the evidence as something else.
Could there be a brain-damage where a subject recognised something explicitly as overwhelming evidence for that P and yet could not come to believe that P? It’s hard to think how this could be if we accept doxastic involuntarism to which your first case was based on.
In the second case, I guess I would like to read the claim as “by the standards of grammar, Agnes ought to say such and such rather than this and that”. But, someone might say that this really isn’t a normative use of ought, after all there can be all sorts of standards and oughts relative to them such that we have ought not to follow them. Maybe the principle applies only to those.
Of course, this is beginning to sound a bit ad hoc.
Finally, for me the best way to think about ought implies can is through reasons. After all, if we ought to do something then this must be because we have sufficient reasons to do it. It is then attractive to think that reasons are fundamentally for ‘judgment-sensitive attitudes’ that react to our judgments to reasons. This would ground ought implies can to reasons imply can because reasons are for attitudes that react to our judgments about reasons. Bart Streumer has recently defended the reasons imply can principle well.
A very minor point: there appears to be a typo here:
I think “if and only” should be “only if”.
Hi Jason,
About some of your cases, I share some of Jussi’s worries.
Also, I find it interesting that you don’t talk about intentions. It seems that (at least, typically) if a person ought to do X, then she ought also to intend to do X. Yet whether one intends to do X is no more under one’s volitional control than whether one believes that P. I cannot, for instance, at will intend to drink a toxin tomorrow knowing that, come tomorrow, I will have absolutely no reason to do so.
I think that the lesson in all this is that, ultimately, we need to show how people can be responsible for attitudes over which they don’t have volitional control, where volitional control over whether one Xs requires that whether one Xs depends on whether one wills/intends to X.
Regarding freedom and responsibility over attitudes over which we have no volitional control, you might want to look at the following if you haven’t already:
PETTIT, P. AND SMITH, M. (1996). “Freedom in Belief and Desire.” Journal of Philosophy 93: 429-449.
SMITH, A. M. (2005). “Responsibility for Attitudes: Activity and Passivity in Mental Life.” Ethics 115: 236-271.
SMITH, A. M. (2008). “Control, Responsibility, and Moral Assessment.” Philosophical Studies 138: 367-392.
STEUP, M. (2008). “Doxastic Freedom.” Synthese 161: 375-392.
Maybe I’m in the minority on this (although I think both Steve and Jussi hint at this view), but I would deny that it would be fair to say that the either the Believer or the Grammatizer ‘ought’ to do what is being claimed. Given that both have disabilities that prevent proper belief/grammar, I’m not sure that saying they ‘ought’ to do something they (by structure of the example) absolutely can’t do really makes sense. It may be a quirk of language, but it still doesn’t strike me as far to either person.
Thinking about it another way, it makes sense to say that I ought to be able to utilize calculus, although I probably wouldn’t be able to since it has been a long time since I’ve studied it, and I’ve sadly forgotten a good deal. But I don’t think anyone would say that a severely mentally retarded person the same age as me ought to be utilize calculus, unless the ‘ought’ is fairly meaningless. (A ‘ceteris paribus ought’?)
I’m not sure if the REASON for the disability/inability comes into play here. In both of your cases, the problem comes from no fault of the agent. Same with mental handicaps. But I wouldn’t say the same about my inability to do calculus…if I were to be more intellectually responsible and rigorous, I could keep my math skills up. And if you modified the examples to change the cause of the disability (if, for example, the person’s brain injury that prevents them from being able to use grammar correctly was caused by careless and unsafe motorcycle riding without a helmet), I might change my view on the ‘ought’.
Just a quick (and probably ill-informed) thought: I’m interested that you introduce the idea of blameability here. But it could be that there’s more than one kind of “ought”: moral oughts where it’s blameable not to p, but inability is an exculpation; and non-moral oughts where it’s perhaps normal or desirable to p, but where inability is an explanation. “Ought” in this second sense would refer to what we expect to be the case all being equal, but which we chalk up as anthropologically interesting rather than morally worrisome when our expectation is confounded.
Horribly unclear, I know. But clear enough, I hope.
I see two versions of an “ought implies can” principle in Jason’s post. The first applies to token instances of belief formation (or, in the moral case, to token instances of intention-formation or action, say). This formulation says that in any token case, I can be epistemically required to believe that P only if the required conditions are present such that I am able to believe that P.
The second formulation is implicit in Jason’s observation that “you might say that I am in some sense physically or psychologically capable of believing that P–it is not incompatible with some important or essential description of my psychology that I believe that P.” Here, “ought implies can” is not about token instances, but about more general features of the epistemic or moral agent. I’d go a step further and say that this version of “ought implies can” should be understood as applying not to applications of an epistemic or moral theory, but rather to the choice of theory: if an epistemic or moral theory assumes features of agency that humans do not possess, then it cannot serve as a source of justifications for us.
With this is mind, look back at the defect cases. What I want to say about these, in light of the latter formulation of “ought implies can,” is that these are cases of people who fail in some respect to be epistemic agents. A person with a form of brain damage that causes them to systematically believe or fail to believe in ways that diverge from the relevant epistemic norms is to this extent and in this manner irrational.
Following Eric R., it seems odd to say of such a person that they ought to believe differently – they cannot! It would be like saying the lion ought not kill the gazelle. We ought not kill (in the relevant conditions), only because we are moral agents, and the lion is not.
So the upshot here, I’m claiming, is that in the defect cases the correct conclusion is not the failure of “ought implies can” (properly understood), but rather that the victims of the defects fail to be – to the extent determined by the defect – epistemic agents. It matters that it is a systematic defect, because we all fail to be rational from time to time, and this does not mean that we lack agency, but only that we have made a mistake. I think Jussi’s Japanese soldier case is an interesting middle ground between neurological defects and everyday mistakes – perhaps we need an account of epistemic norms at the level of culture? – but I’ve already written too long a post.
-Pete
In the epistemic case you think
D ought to believe P where D has decisive evidence that P even though D can’t form the belief that P due to some neurological defect.
In the equivalent moral case do we say that
D ought to V where D has a duty to V even though D can’t V due to some neurological defect?
If we are right to say the first thing, we ought to say the second as well. I can see some sense in saying these things. In legal philosophy, many people say about the second case that D’s failure to V was wrong, but excused, and we could say something similar about the first case too.
But the much more radical inability in the case of shooting magic fireballs is more like a different kind of epistemic case where we are less likely to conclude that ought implies can. For example, answering some mathematical problem, C, may be beyond human capacity. Suppose that the answer is A. If a person is presented with the problem and asked the answer, we don’t say that she ought to say that the answer is A.