Does "ought" imply "can" - Free Will

[Kriminal99]

In another thread I was presented with the argument that Free will is proven by an argument that took as one of its "trivial" premises that "ought" implies "can".

 

A Proof of Free Will

 

That is if it true that someone "ought to do something", then it must also be true that they can do it.

 

I believe a determinist viewpoint is at odds with this idea, therefore a proof cannot simply assume it to be true.

 

You can't do it without motivation

 

"Ought implies can" typically relies on the idea that "can" only refers to a persons physical ability to perform tasks. IE if it is not physicaly impossible to perform a task then you can do it. However the a person may be unable to perform a task for other reasons, such as not knowing how, or not having a reason to.

 

Two common definitions of "ought"

 

The idea is that people make statements like "Person S should/ought to do A" as a means to try and influence S's future behavior, but it was not actually possible for S to have done A before because he didn't know that anyone would have wanted him to or he didnt know how or maybe he did know but he just didn't want to and does not control what he wants directly.

 

On the other hand ought is sometimes used such that it doesn't matter if the person can do what he ought to or not. For example, a murderer should stop murdering people. This is a different use of ought than above, but a commonly accepted one. Therefore we must design our approach to consider each of these two commonly used definitions of ought.

 

Ought = 1) false OR 2) you should do X in the future

 

So from here you can go in 2 different directions. You can say that all statements of the form "S ought to have done A" are false, because S couldn't have done A when he didn't know he was supposed to, didn't know how etc. Or you can alter the meaning of ought to reflect its practical use - ie ought = "someone should tell S to do A" or if you are talking to S, "S, do A in the future".

 

If 1) there is no ought, If 2) "ought implies can" = false

 

If you state that all statements of the form "S should do A" are false, then "ought implies can" is true, but trivial because it is never true that someone "ought" to do something they did not do. If you take the more natural route and just alter ought to be a means of altering future behavior, then ought implies can is false because though you might tell someone they should have done something to get them to do it next time, they actually couldn't have done it this time.

 

I was also presented with the following defense of the "ought implies can" principle,

 

http://www.public.iastate.edu/~vrana...papers/OIC.pdf

 

Here the author simply assumes "can" excludes any psychological inability to perform a task which is at odds with the deterministic viewpoint.

 

I was informed that this last paper is not meant to convince a determinist, and that ought implies can is preserved in conjunction with determinism using the out that perhaps everyone does do what they ought to. In this case ought implies can cannot be used to prove free will as in the original proof - since it is never true that anyone ought to do something other than what they do. In fact, in this case OIC is not really useful for anything since it is never true that someone "ought" to do something other than what they do.

[owl]

Since I'm the author of the piece Kriminal has referred to, I'll try to make a few helpful remarks.

 

I don't think Krim succeeds in giving a genuine counterexample to the "'ought' implies 'can'" principle (OIC). In his first example, where the student didn't know that he was expected to take the bus, I think it's false to say the student could not have come to class. Not knowing that someone wants you to do A does not make one unable to do A. "I didn't know I was supposed to" is a different excuse from "I couldn't have".

 

In the second example, where the student is physically unable to come to class, I think it's false to say that he should have come.

 

However, here are a few related ideas that might be true, and that could easily be confused with the denial of OIC:

 

1) That it might sometimes be practically useful to say that someone should have done A even though they could not do A. Perhaps it would be useful because it would modify their future behavior. This wouldn't show that it's true; it would just show that it can be useful to say what is false.

 

2) That one should sometimes try to do something that one cannot do. Here's a possible case: A surgeon in the hospital emergency room believes that patient X probably cannot be saved. Therefore, he doesn't bother trying. People criticize him for this. Suppose later investigation (the autopsy, perhaps) reveals that the surgeon was correct: at the time the patient was brought in, he was already too badly injured to be saved, no matter what the surgeon had done. People might say: "You still should have tried."

This isn't a counterexample to OIC. The surgeon couldn't have saved the patient, but he could have tried to save the patient. It's true that he should have tried, but it's not true that he should have successfully saved the patient.

 

3) That sometimes, it would have been better if one had done A, but one could not have done it. It would be better if I were to live forever, but in fact I can't live forever. That's true. But it's not the case that I "should" live forever.

 

If we distinguish claims (1), (2), and (3) from the denial of OIC, we'll be less tempted to think there can be an exception to OIC.

 

And OIC is very intuitive. Consider another case: A parent in our society, in normal conditions, has an obligation to get their child vaccinated against measles. A parent does not, however, have an obligation to vaccinate their child against cancer. Since parents generally have obligations to care for their children, and since cancer is an extremely serious problem, the risk of which is greater than the risk of measles, what explains the lack of an obligation to prevent one's child from getting cancer? It's very plausible to say that the reason is that the parent in fact cannot vaccinate the child against cancer, since no such vaccine exists.

[owl]

This may not be the place for this comment, but the earlier thread is now closed, so:

 

On Bell's theorem, Aspect's experiment, and determinism: Bell's theorem (& Aspect's experiment) shows that no local, deterministic theory can be true. But it does not refute nonlocal, deterministic theories, such as Bohm's interpretation of quantum mechanics. Furthermore, you probably have to give up locality anyway, whether you're a determinist or not. I discuss that in the essay here, which also explains Bell's theorem: home.sprynet.com/~owl1/qm3.htm

[CraigD]

This may not be the place for this comment, but the earlier thread is now closed, … I discuss that in the essay here, which also explains Bell's theorem: home.sprynet.com/~owl1/qm3.htm

A discussion of this appears in a still open thread, beginning with this post. Ughaibu and I were hoping you’d join the discussion here at hypography – welcome!

[phoenixbyrd]

I'm not trying to be rude here, but I've noticed a slight trend on these forums. No one likes dictionaries.

 

Does ought imply can? Good question. Let's define ought.

 

ought - Definitions from Dictionary.com

 

ought1 /ɔt/ Pronunciation Key - Show Spelled Pronunciation[awt] Pronunciation Key - Show IPA Pronunciation

–auxiliary verb

1. (used to express duty or moral obligation): Every citizen ought to help.

2. (used to express justice, moral rightness, or the like): He ought to be punished. You ought to be ashamed.

3. (used to express propriety, appropriateness, etc.): You ought to be home early. We ought to bring her some flowers.

4. (used to express probability or natural consequence): That ought to be our train now.

–noun

5. duty or obligation.

 

The usage of the word here is pretty much in error with the given definition. Not only is the usage wrong, but the implications of what it implies or does not imply is also wrong. But to etertain the idea ..

 

I ought to eat an apple. While I most certainly CAN eat an apple, why would I? Why should I OUGHT to eat an apple? What would be my motivation? Hunger perhaps?

 

I ought to kick that guys ***. While I most certainly CAN kick that guys ***, why would I? Why should I OUGHT to kick that guys ***? What would be my motivation? Stole my girlfriend perhaps?

 

Ought and can are seperate from each other. Ought does not imply can, which is readily obvious when you understand the definition of the word and it's usage.

 

Again, not trying to be rude, but some people here need to look up certain words and how they are used in the english language.

[ughaibu]

As I read them, all the definitions you posted imply can. And examples in which the "ought" is unestablished are irrelevant, the use of ought is presupposed by the question. If you're suggesting that language has a commutativity akin to that of arithmetic, you're mistaken, that ought implies can does not require that can implies ought.

[phoenixbyrd]

Crack open a dictionary and look up ought and can. Both are distinctivley different words with different meanings and usage which is readily made obvious when you understand the definitions and their usage.

 

Ought implies motivation for example. It doesn't imply anything else.

 

Can you tell me what can is and what it implies?

 

Dictionaries are wonderful tools that everyone should have the knowledge of how to use one. If you don't understand a word or how it's used you can always look it up for furthur clarification on that specific word rather then just making up any old meaning you wish it to mean in a futile attempt to make your point. The word ought and it's meaning/usage is a pretty simple concept to grasp.

[ughaibu]

Which of the following statements makes sense and why:

1) you ought to remember my birthday

2) you ought to remember your previous post

[phoenixbyrd]

Both make perfect sense. The only issue I see is that I don't know your birthday. In both instances your implying a duty. Look at the definition I posted. In none of the definitions given on the linked site do any imply or define ought as meaning can.

[ughaibu]

What is the sense of "you ought to remember my birthday" if you dont know when my birthday is?

Nobody is suggesting that 'ought' means 'can'.

[phoenixbyrd]

If I knew your birthday then the sentance would make perfect sense.

 

The topic says does ought imply can - free will.

 

I'm trying to show that ought does not imply can and most certainly not in the case of free will.

 

So entertaining the idea that I do know your birthday ...

 

Say I forgot the exact date, didn't commit to memory as something important that I should remember readily.

 

While I can remember the exact date if I tried to remember: "What was his birthday again" is not the same as I ought to remember your birthday. I have no reason to ought to remember it. No motivation. Unless of course I knew your birthday was comming up soon, then I have a motivational reason to ought to remember it.

 

In the case of free will, I didn't just choose to remember it, I had a reason to remember it. Something caused me to remember your birthday in which case being the knowledge that your birthday was comming up soon. No free will on my part.

[ughaibu]

The whole point is that if you dont know my birthday then you can not remember it and that it makes no sense to say "you ought to remember my birthday", therefore ought implies can.

[phoenixbyrd]

How does ought imply can in that situation when I can't remember your birthday nor have any reason to ought to remember it?

 

More importanly, how does the ought imply can relate to free will in that situation.

[ughaibu]

In that situation it has nothing to do with free will and, as you have now observed yourself, if there is no 'can' then there is no 'ought'. This is what is meant by 'ought implies can'. I suggest you read post 1 again and click on it's links in order to get the context of this thread.

[phoenixbyrd]

Personally I think it should read can implies ought. That makes much more sense. If I can save a little kids life, then I ought to do so. Ought implies can just makes no sense when given the definition of the two terms. Seeing as how the situation described doesn't even apply to free will, having the concept and free will in the same thread title also doesn't make much sense.

[ughaibu]

You can kill yourself, does it follow that you ought to?

[phoenixbyrd]

depends really. Do I have terminal cancer with only 5 agonizing days left to live?