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OSWY:
This is an idea that has been recycled now for well over 200 years, but it is no less a fallacy itself for all that.
http://en.wikipedia.org/wiki/Is-ought_problem
But, it is very easy to derive an ought from an is; logicians have been doing it for years.
Here is a one premiss argument that does just that:
Premiss: All cars require lubricants to run well
Conclusion: Therefore, if you want your car to run well, you ought to put oil in the engine.
There are countless other arguments like this, and better.
So, can we bury this old chestnut now?
Last edited by Rosa Lichtenstein; 10th September 2008 at 15:49.
You believe that all cars require lubricants to work well
and
You believe cars ought to work well
then
You believe Cars ought to be lubricated.
Sorry Rosa, the 'ought' is in the second premise. SInce its in one of the premises you have not derived ought from is - cant be done.
"Dixi et salvavi animam meam" - quoted by Marx
"Things rarely work out well if one aims at 'moderation'..." - Engels
"By and by we heare newes of shipwrack in the same place, then we are too blame if we accept it not for a Rock." Sir Philip Sydney
"The most to be hoped for by groups who claim to belong to the Marxist succession (...) is for them to serve as a hyphen between past and future....nothing can be held sacred – everything is called into question. Only after having been put through such a crucible could socialism conceivably re-emerge as a viable doctrine and plan of action." - Van Heijenoort
GIL:
Nice try, but that was not my argument.
I think it is...the conditional conclusion just folds in the second premise. WIthout the 'if' clause you conclusion does not follow, for example:
All cars require lubricants to work well:
Therefore all cars ought to be lubricated
Clearly this does not hold
(Do you think there is something slightly freudian in using an example that involves lubrication on a thread that is ostensibly about a sex-related issue ?)
"Dixi et salvavi animam meam" - quoted by Marx
"Things rarely work out well if one aims at 'moderation'..." - Engels
"By and by we heare newes of shipwrack in the same place, then we are too blame if we accept it not for a Rock." Sir Philip Sydney
"The most to be hoped for by groups who claim to belong to the Marxist succession (...) is for them to serve as a hyphen between past and future....nothing can be held sacred – everything is called into question. Only after having been put through such a crucible could socialism conceivably re-emerge as a viable doctrine and plan of action." - Van Heijenoort
GIL:
Not so; you can propose your own argument till the cows evolve. Mine does not have the suppressed premiss you say it does.
But even your argument can be conditionised:
Premiss: You believe that all cars require lubricants to work well
Conclusion: So, if you believe cars ought to work well then you believe Cars ought to be lubricated.
I do not know why you are trying to argue this one out; we have known of such counter-examples since at least the work of Arthur Prior.
Im arguing cos its not true. Any of this stuff I have read just isnt right. What they describe as a conclusion is not a conclusion, but contains a hidden premise.
The answer to the is/ought fallacy is not that you can derive an ought from an is, but that its trivial that you cant, since the basis on which you cant is abstracting from agents. Agents, necessarily generate 'oughts' - to be an agent is to have the capacity to formulate objectives, to describe an agent is - in part - to describe given objectives. The desire to deny the is/ought distinction comes from an insistence that the objectives they formulate follow logically from their nature, i.e. from what is. That is not so - logic and description cannot model the formulation of objectives. Purpose is not logical in that sense.
Thus the car sitting in the museum no one ever intends to use again does not need to be lubricated to 'work' effectively.
"Dixi et salvavi animam meam" - quoted by Marx
"Things rarely work out well if one aims at 'moderation'..." - Engels
"By and by we heare newes of shipwrack in the same place, then we are too blame if we accept it not for a Rock." Sir Philip Sydney
"The most to be hoped for by groups who claim to belong to the Marxist succession (...) is for them to serve as a hyphen between past and future....nothing can be held sacred – everything is called into question. Only after having been put through such a crucible could socialism conceivably re-emerge as a viable doctrine and plan of action." - Van Heijenoort
Gil:
It does so in re-configured arguments, but not mine.
Sure, that this one way of slicing it, but it is not mine.
But, I am not sure what you mean by this:
Logic is about what follows from premisses, so it will depend on those.
Now take this stencil:
Premiss: All and only Fs are Gs.
Conclusion: If you ought to F you ought to G.
["F" and "G" are predicate letters (restricted to the domain of the do-able) -- I'd employ 'phi' and 'psi' here if there was a sophisticated character here set we could use).]
But is it a valid schema?
I cannot see it generating falsehoods from truths, can you?
Its a valid schema
So (probably) is the following:
I now realise Im guilty of hikacking this thread
If one always ought to stop arguing when one realises one has hijacked a thread, I should now stop arguing
.....But it doesnt actually tell me what I ought to do - no ought has been derived.
Thus in your example to derive an 'ought' conclusion (I ought to G)...I have to add the premise, 'I ought to F.
Discussion here: http://peasoup.typepad.com/peasoup/2006/03...t_gap.html#more
"Dixi et salvavi animam meam" - quoted by Marx
"Things rarely work out well if one aims at 'moderation'..." - Engels
"By and by we heare newes of shipwrack in the same place, then we are too blame if we accept it not for a Rock." Sir Philip Sydney
"The most to be hoped for by groups who claim to belong to the Marxist succession (...) is for them to serve as a hyphen between past and future....nothing can be held sacred – everything is called into question. Only after having been put through such a crucible could socialism conceivably re-emerge as a viable doctrine and plan of action." - Van Heijenoort
Hi Gil,
I get the sense you are confusing Rosa's
with some variant of:
Premise 1: All cars require lubricants to run well.
Premise 2: You want your car to run well.
Conclusion: You ought to put oil in the engine.
The two syllogisms are quite distinct, although admittedly it's not clear to me how the former obviates the is-ought problem. After all, the "is" premise says nothing about whether we in fact want (or should want) our car to run well.
And Rosa, which criticism of the is-ought problem do you subscribe to? Wouldn't any ethical inquiry worth its salt ask the question: "Do you want your car to run well", not just "what ought we to do to get our car to run well".
百花齐放
-----------------------------
la luz
de un Rojo Amanecer
anuncia ya
la vida que vendrá.
-Quilapayun
LOL
You do realize that "ought" is being used in the moral sense, right?
R:
No problem:
All human beings require love in order to flourish.
Conclusion: Therefore, if you want your child to flourish, you ought to love her.
Now, this moribund idea is well past it cremation date.
Anyone got a box of matches...?
GIL:
Ah, the old 'move the goal posts' ploy.
But:
Premiss: All counterexampes are a pain
Conclusion: Therefore I ought to add a few premisses to screw around with them
Sure, that's an invalid argument, but it's what you keep doing.
MS:
First: it's not a syllogism.
Second: I subscribe to neither.
Recall, I reject all philosophical theses as non-sensical.
Particularly those in ethics.
Rosa
I haven't grasped your answer to my point that, despite the presence of the relevant word, the proposition:
if you believe cars ought to work well then you believe Cars ought to be lubricate
is not an ought statement of the type to which the is/ought argument applies. There is no derivation of an 'ought' from this process of reasoning.
(I accept btw the criticism of this whole debate that it tends to use non-moral examples and moral (or ethical) examples have some distinctive characteristics, in particular not always being instrumental reasoning, but I think the debate can be held in these terms, up to a point, notwithstanding that.)
"Dixi et salvavi animam meam" - quoted by Marx
"Things rarely work out well if one aims at 'moderation'..." - Engels
"By and by we heare newes of shipwrack in the same place, then we are too blame if we accept it not for a Rock." Sir Philip Sydney
"The most to be hoped for by groups who claim to belong to the Marxist succession (...) is for them to serve as a hyphen between past and future....nothing can be held sacred – everything is called into question. Only after having been put through such a crucible could socialism conceivably re-emerge as a viable doctrine and plan of action." - Van Heijenoort
Oh dear, there is life after death!
I ignored it because it is just a reprise of the debate that went on several generations ago, wherein logicians provided counterexamples and the defenders of Hume moved the goalposts each time.
I addressed the claim that it is not possible to derive an ought from an is.
I have done so, several times.
You keep altering the examples.
Fine, your examples do not work, mine do. [In the sense that they address the original aim, not the moved goalposts.]
You say there is no derivation of an ought here; here it is again:
Now, this has nothing to do with 'beliefs', so I do not know why you have introduced that red herring.
The derivation works independently of the existence of any believers.
You will be attacking Modus Tollens next on the pretext that one has to believe the premisses first!
But here you are inserting an "if you want your car to...".
The is/ought fallacy states that an observed fact does not of itself provide values. What you're doing here is not presenting a premiss as fact but a premiss as a fact with a piggybacking value.
It may be a fact (i.e. an 'is'that cars run well on lubricant.
It does not inevitably follow from the above premiss that you are compelled (i.e. 'ought'
I think the is/ought fallacy is pretty watertight, but I've got to go out now to a BBQ!
Later people.
It is not the consciousness of men that determines their existence, but their social existence that determines their consciousness. Karl Marx.
i agree with Rosa on this one.
what i would point out is that there are reasons for thinking there exists in the natural world a certain kind of non-moral normativity that can generate "should" or "ought" statements from factual premises. for example, a heart is adapted thru evolution to pump blood. to say it is adapted to this is to say this is what it is for, this is it's biological function. and from this we can infer this is what it should do or ought to do. and if it isn't doing this sufficiently to keep the animal alive that it is in, then it is not doing what it should do. it is defective, a bad heart.
The emancipation of the working class must be the work of the workers themselves.
Thankyou for those comments Syndicat, and I am tempted to go along with your examples (i.e., those related to biological functions), but to do so would, I am afraid, be to re-introduce teleology into nature.
OSWY:
But, that insertion, if such it may be called, is in the conclusion, not the premisses.
So, my example does derive an ought from an is.
And you need to question, too, the link (one which is, I think, almost universally held) between 'ought', morality and 'values'.
Now, I have ignored the latter term (since it is hopelessly vague), and have just concentrated on the logical issue at hand (and hence on the alleged 'fallacy'
I have absolutely no interest in concentrating on the bogus issue of the connection betwen facts and 'values', since the latter term, as I have said, has nothing to do with morality, or with 'ought'.
But, check out the end of this post -- where I show how to derive a 'value' from a fact.
Well, who mentioned compulsion?It may be a fact (i.e. an 'is'
It does not inevitably follow from the above premiss that you are compelled (i.e. 'ought'
No 'ought' compels anyway.
It should not be news to you, but people all over the world give the finger to what they 'ought' to do, and they do so in their millions, and every day.
So, this objection of yours is not in fact about the is/ought 'fallacy', but about the alleged impossibility of deriving a compulsion from an 'is'. [But I can do that too!]
As I said to Gil, defenders of Hume here have to keep moving the goal posts -- but, in this case, you move to a new playing field!
Well, you will need something a little more substantial than just a 'think' to back you up here.
And, are you 'compelled' to go to that BBQ?
--------------------------------
How to derive a 'value' from a fact:
Premiss: All cats are mammals
Conclusioin: If you 'value' your cat, you 'value' a mammal. QED
-----------------------------
Obituary Notice: I regret to announce that Hume's obscure theory has passed away after a long and debilitating illness.
The funeral will be held at RevLeft, today
Send no flowers.
Rest In Pieces...
however, in evolutionary biology the concept of a function or of being adapted "for" something, is reduced ultimately to the action of material forces. so evolutionary biology doesn't require some un-reduced concept of teleology in nature.
to say that it is the function of this heart to pump blood is to say:
1. this heart is a copy of a structure that has occurred in ancestors of this animal
2. those previous hearts pumped blood and this was an important explanation
for the survival of those animals
3. this fact (2) explains why this heart exists, i.e. why this animal has a heart.
That is what it means to say the function of the heart is to pump blood. Thus there is no unreduced teleology.
The emancipation of the working class must be the work of the workers themselves.
