Wednesday, June 17, 2015

'Ought' implies 'can'?

I am sick. Here's a heartening argument: Next week I have some teaching and I can't teach while sick. I ought to do the teaching. Ought implies can. So I will be well by next week.

One gap in the argument is that my doctor may tell me I'm not sufficiently infectious to be unable to teach. But that can't be all that's wrong with the argument.


Richard H said...

If oughtness is rooted in a monetary environment, "I owe..." then it certainly does not imply "can."

Alexander R Pruss said...


More seriously: Maybe, bankruptcy is a way of acknowledging that even there ought implies can? You can either pay what you ought or declare bankruptcy? (Doesn't work for non-bankruptable debt, though.)

Richard H said...

Maybe the temporal dimension should be acknowledged. The span of "oughtness" (or "owingness") is from To1 to ToN; the span of ability ("Can") may also begin at To1, but may not extend all the way through to ToN.

Then I also wonder how much difference it makes whether this question be framed in an impersonal or a personal system. In a personal system one might imagine that the person conferring the ought obligation is doing so based on a judgment that the recipient, the one entering the ought relation, CAN do/pay what is expected. The one accepting the obligation (in at least some circumstances) has an option of entering or NOT entering into the ought obligation, based on self-perception of ability to do/pay what is expected. Judgment on either side can be more or less correct.

Unknown said...

It has to do with moral responsibility, not physical ability. I think it's to be understood: a legitimate moral obligation requires (presupposes, etc.) ability to perform or not to perform the action in question.

It is also worth noting that, taken in the abstract, this principle is Pelagian.

Alexander R Pruss said...

Pelagianism is the view that one can get to a state that fits one for heaven by one's own efforts.

Ought implies can is the view that one can do whatever one morally ought to. (And that's of course what's wrong with my initial argument, as the 'ought' there wasn't moral.)

It's far from clear that "'Ought' implies 'can'" implies Pelagianism.

On its face, all we get is the thesis that for every particular sin x, it is possible for one to avoid x. It takes further argument to change the order of the quantifier and the "it is possible" to conclude that it is possible to avoid every sin. And then it takes a yet further argument to argue that if one avoids every sin, then one is fitted out for heaven.

The Catholic tradition has generally denied that sinlessness is all that's needed to deserve heaven. Rather, since heaven is a reward far beyond the human norm, to deserve heaven one would need a virtue far beyond the human norm. It would be Pelagian to say that Adam and Eve were capable of getting to heaven without grace.

Unknown said...

I agree with your final paragraph in terms of RC anthropology, but this was not developed in pelagius' time. But anyway, I'm not sure how that's relevant.

Pelagianism is the rejection of the doctrine of original sin; it is not primarily soteriology. Pelagius wanted as he understood it to protect the justice of God; and this is my point. He believed that guilt for someone else's sin was unjust, and that the moral corruption of sin could not be inherited. Guilt was accrued only on the basis of actual sins committed by individuals, not by a representative (Adam). All this is to protect an abstract notion of justice, that it is unjust to blame a person for (1) someone else's sin(s) (inherited guilt) or (2) for sins committed under compulsion (inherited moral corruption). Since God is perfectly just, it cannot be the case that one ought to be righteous or obedient (meaning that one is accountable for this righteousness, guilty if not) where one is not able to be righteous or obedient. There is a lot more to it, but anyway my understanding is that his principle interest was in this justice and in affirming consistently that God is just (according to this unbiblical principle).


David Gordon said...
This comment has been removed by the author.
Dagmara Lizlovs said...


Here is my take on all this. If you are sick you may be contagious and an "ought implies can" attitude will cause you to "share the love" and give the "gift that keeps on giving". I have a coworker who always comes in sick even if he is half dead. His attitude was back when he was a sailor he was expected to do his duty even if he was sick. He is a complete believer in "ought equals can". No one told him he wasn't on a ship anymore! Needless to say I often up with his germs. On one occasion I picked up his stomach bug on Friday. I went out to shoot some skeet on Saturday. That Saturday evening his stomach bug hit me full force and I got completely cleaned out as I was cleaning out my shotgun barrel. It is perfectly doable to clean a shotgun while being cleaned out at the same time. That was so much fun. Next time that happens, I'll use the occasion to pattern my choke tubes! :-)) Then there was the time where each of us in my Rosary group had some kind of bug. We deliberately gave each other hugs knowing that we were sharing the bugs. So what, we're already sick. I call all this gift that keeps on giving and coming in to work while sick as sharing the love. So go ahead, give the gift that keeps on giving and share the love! "Ought = can"! According to Christian Science disease is an illusion of Mortal Mind! :-) How did I go from "ought implies can" to "ought = can"? It was just one small step.

Chris said...

At the end of finals week, one of my colleagues reasoned, "Failing grades must be reported to academic services by 5pm. I will not grade final exams until Monday, so I have no failing grades to report until then (and hence no failing grades to report on Friday). Therefore, no one in my classes can have failing grades. Everyone wins!"

Alexander R Pruss said...

But the necessary is actual. Hence failing grades will be reported. But if failing grades will be reported, then there will be failing grades.