by Scott F. Aikin and Robert B. Talisse
Ernie: “Is it possible you'll be around after lunch for a quick chat?”
Ernie: “Ok. I'll see you then.”
Bert: “Wait, wait! I didn't say I'd be around after lunch!”
Ernie: “What the heck?!?!”
This is a case of a conversational misfire, and although errors of this kind are the central ingredients of the humor of people like Woody Allen, Larry David, and Lewis Carroll, such misfires can create a good deal of argumentative and philosophical confusion. Let's start with a quick diagnosis of the misfire above, then we'll identify why this kind of misfire is common. We'll finish by pointing to a few philosophical lessons.
The core of the error above lies in this: Bert assents to the (mere) possibility of being around after lunch for a meeting with Ernie. Assenting to the possibility of a meeting is not assenting to the actuality of a meeting. Consequently, Bert thinks that his assent to the possibility of a meeting does not place him on the hook for attending any actual meeting. And so, from this perspective, Ernie has made a modal error; he has fallaciously inferred actuality from possibility. Among philosophers, that's a rookie's mistake.
Yet it seems that Ernie is well within his rights to respond with incredulity at Bert's final response. Even though Bert is correct about the modal relation between possibility and actuality, Bert is nevertheless being obtuse, and it's perfectly reasonable for Ernie to respond with exasperation. To diagnose the misfire simply as the result of Ernie's modal confusion leaves unexplained why Ernie so readily commits the inference and why it seems that Bert is obtuse not to recognize it. Note that it also fails to capture what is mildly humorous about the exchange.
In order to get a better sense of what's going on, we must look beyond the semantics of Bert's assertions, and attend to the pragmatics of Ernie and Bert's exchange. To explain, semantics is an account of the truth-functional and formal properties of sentences and assertions, while pragmatics is an account of the uses to which sentences and assertions are put within contexts of communication. Given that the case we are interested in is a conversational exchange of sentences, we need to look at both Bert and Ernie's contributions.
Bert's contributions must be interpreted according to the pragmatics of assenting to a possibility whose actuality is up to him. Our line of thought is this: In assenting to the possibility of a proposed post-lunch meeting with Ernie, Bert asserted (even though he did not explicitly say) that he would plan to meet with Ernie sometime after lunch. More generally, when one reports that some proposed future event, X, is possible, and when X's actuality is in addition contingent upon our own actions, one is reporting that one plans to or wants to bring X about. Consider a few additional examples:
You should ask me out. I might say yes.
If you wash the dishes tonight, it's possible that you can borrow the car.
I can make that happen for you.
In these cases, affirming possibilities whose actuality is primarily contingent on our own wills and actions carries the conversational force of positively agreeing their actualization. Hence we can see why Ernie makes the inference he does and why he is perplexed with Bert's reply. Despite what Bert may think, he indeed did say (implicitly) that he would be around for a meeting with Ernie after lunch!
A question lingers about Ernie. Why frame the proposal to have a meeting after lunch in terms of a possible meeting at all? The key here is to note that Ernie's opening locution is not simply a call for information about Bert's afternoon plans, but a request that Bert do something other than what he had been planning. Framing the request in the modality of possibility has the conversational effect of mitigating its intrusiveness or softening what might otherwise appear to be a demand. Because it is posed as a question of the meeting's possibility, Ernie's request allows Bert the option of declining the request by saying the meeting is not possible. Ernie is just being polite by asking about the meeting's possibility instead of issuing an imperative or taking a more direct route:
“Meet me after lunch. We have to talk.”
“We have to meet after lunch.”
“I want you to meet me after lunch.”
Again, Ernie is just being polite when he puts the meeting in a modal context of possibility. Consider analogous versions:
“Can we meet after lunch?”
“Is there any way to meet after lunch?”
The modal terms here serve to lighten the load of imposition. Ernie is still giving Bert a stronger matter to consider (an actual meeting), but directly asks only about its mere possibility. We can see the difference of etiquette in modalizing the directive contents:
“Turn up the heat.” vs. “Can you turn up the heat?”
“Let's have ice cream for dessert,” vs. “Is there any way we could have ice cream for dessert?”
Again, the latter are the more polite ways to ask for what you want.
We take these to be fairly obvious points about the importance of pragmatics in understanding each other's utterances. But maybe there are deeper philosophical lessons lurking as well. One such lesson might be that our modal terms (such as can, might, able, possible) often serve expressive, conversational, and pragmatic purposes, and do not aim to track metaphysical commitments at all. To wit:
“I can't do it” sometimes means I won't do it, because I don't want to do it.
“I'm able to do it” sometimes means I will do it.
“It ought to rain this afternoon” sometimes means I predict it will rain this afternoon.
“You can't do that” sometimes means you shouldn't do that.
Yet in other contexts our modal terms have both a pragmatic or expressive function and a metaphysical one. Consider in particular the age-old philosophical doctrine of ought implies can. Just as Ernie took actuality to follow from possibility, the ought-can principle contends that a certain form of possibility follows from a certain form of necessity. The idea is intuitive when expressed within the context of moral requirements, where it was first developed. To explain: It seems obvious that whatever I morally ought to do has to be something that I can do; morality cannot require of me actions that are strictly impossible. For sure, ought implies can derives some of its intuitive force from the fact that many ought-statements are uttered within advice-giving contexts. Consider:
The poor certainly suffer from their poverty. I have a solution: they ought to simply stop being poor.
Do you regret not doing the right thing when that robbery was happening? You ought to go back in time and do the right thing.
You promised to be at a wedding in New York and a birthday party in Miami, both on Sunday at noon? That's easy: just do both.
Alcoholism is destroying your life. Stop wanting booze.
These statements are not even bad advice; they hardly count as advice at all, as they are directives one simply cannot follow. They accordingly fail to say what anyone ought to do.
But now consider whether incapacity always defeats a normative requirement. Kleptomaniacs can't help themselves, but still they shouldn't steal. Alcoholics should stop themselves from having another drink, but they can't. Humans should consistently compute conditionals properly, but Wason's four-card selection task shows we can't. We should make moral judgments consistent with and according entirely to moral considerations, but apparently we can't (it seems our moral judgment is regularly determined by non-moral factors, such as ambient smell.
When one says that kleptomaniacs ought to stop stealing, or alcoholics ought to stop drinking, one is affirming an ought in a non-pragmatic sense; one is indeed affirming the possibility that the kleptomaniac and alcoholic can be reformed, but, crucially, one is not giving advice. More importantly, one is also not implicitly requesting that the kleptomaniac and alcoholic act so as to bring some result about. Rather, one is directly affirming a moral requirement and appealing to a firmly modal sense of possibility. That is, one is speaking in a decidedly philosophical register. And just as there are deep and longstanding philosophical debates over the semantics of modal terms, there are also similar debates, occasioned by exchanges like Bert and Ernie's, over how to tell the difference between philosophical and ordinary conversation.