Friday, 16 May 2008

Hume's Is-Ought Problem

Having dealt with Moore's Naturalistic Fallacy yesterday it is appropriate to deal with Hume's Is-Ought problem with which is is often confused. However unlike Moore's argument there is nothing false about Hume's argument, it just does not lead to problems as an ethical naturalist, but it is still fatal to many subjective systems that falsely claim they are objective such as Divine Command and Randian Objectivism.

The Is-Ought Problem
There is no better reference that what Hume himself said as an afterthought in his "A Treatise of Human Nature"
In every system of morality, which I have hitherto met with, I have always remark'd, that the author proceeds for some time in the ordinary ways of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when all of a sudden I am surpriz'd to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence. For as this ought, or ought not,that expresses some new relation or affirmation, 'tis necessary that it shou'd be observ'd and explain'd; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.
and I wholeheartedly agree with this. To put it simply you can't conclude with an ought given only is premises.

You can derive an 'ought' from an 'ought'
However there is nothing wrong if there is an ought in the premises to draw a further ought in the conclusion. As John Searle says in "How to derive an 'ought' from an 'is' "
Put in more contemporary terminology, no set of descriptive statements can entail an evaluative statement without the addition of at least one evaluative premise.
However unlike Searle we do not need to attempt to do this, indeed I think Searle was mistaken in his argument (see the link above) but that is outside the topic of this post (I will examine it in the future, analyzed in terms of Desire Fulfillment).

Another reference, which incidentally demolished Randian Objectivists arguments over deriving ought from is - some of them say, fallaciously, that all 'is's are' oughts' (but more on this in a future post) - in "Ayn Rand and the Is-Ought Problem" by Patrick M.O'Neil:
It should be noted that, although many philosophers speak as if the is-ought problem were a problem in logic, the question does not belong to the domain of the science of logic at all. The problem can, of course, be expressed in logical terms, for the impossibility of deriving an "ought" from an "is" can be rendered as the inability to reach prescriptive conclusions from descriptive premises. Despite the use of the terminology of logic in setting up the problem, however, there exists no necessity from the point of view of the science of logic alone why one should expect to be able to derive an "ought" from an "is." No paradox or antinomy results from this inability, and prescriptive conclusions can be produced by the expedient of utilizing a prescriptive premise."[my emphasis]
And this is the approach here.

Natural Oughts
As Tom Clarke from the Center for Naturalism says
Clearly normativity is natural, in that ethical rules or norms are based in human biological needs and innate psychological dispositions, modulated by culture.
So what are these natural norms ? An agent acts to fulfill the more and stronger of their desires, which includes all the biological needs, innate psychological dispositions and cultural modulations, given these actions - whether they achieve fulfillment or not - the desire is the "natural norm" (or reason to act), if they do not have their desire they have no reason to act and would not so act. So an ought is nothing other than a reason to act, since for agent to ought to F, is for them to have a reason to act to F - and here, in Desire Fulfillment, a reason to act is nothing other than a desire.

A theory of value is a theory of prescription
So in developing a theory of value - the desire fulfillment theory of value - we have also developed a theory of prescription - a theory of reasons to act - and the theory of value describes these prescriptions - namely the desires and how they are fulfilled (or not).

So in analyzing any situation, once one has identified the relevant desires (the reasons to act), significant desires (the materially affected desires) , the states of affairs and their relations, one can evaluated and draw conclusions this in terms of oughts - in terms of desire fulfilling desires and desire thwarting desires. Since one is starting with oughts (desires) in the premise, there is no issue with ending with such oughts in the conclusion.

So Hume was quite correct, one cannot derive 'ought' from 'is' and any philosophy which does this is a "vulgar philosophy". Desire Fulfillment is no such philosophy since it does not derive 'ought' from 'is'.


The Barefoot Bum said...

Put in more contemporary terminology, no set of descriptive statements can entail an evaluative statement without the addition of at least one evaluative premise.

Searle correctly identifies the crux of the biscuit. Justifying the evaluative premise, though, is the difficult bit.

Clearly normativity is natural, in that ethical rules or norms are based in human biological needs and innate psychological dispositions, modulated by culture.

This is a controversial statement; while it might be true that normativity is natural in this sense, it is definitely not clear. Nor is it clear that Clarke's assertion here is substantive. It seems to me that human biological needs, psychological dispositions and social, cultural and legal constructs might well exhaust the study of ethics: Once we have understood how these factors have caused our ethical beliefs, there is little more for the philosopher to say about ethics.

You run the risk of jumping out of the frying pan of the Naturalistic Fallacy and into the fire of the Adaptationist Fallacy.

martino said...

Desire Fulfillment is a proposed method to make these "natural norms" clear.

As for the adaptationist fallacy I am not using or relying on biological determinism in this analysis.

I am saying that desires are evolved,biological capacities of human agents but the more and stronger of the desires that these agents act upon is also a consequence of cultural and social forces. That is desires are the proximate biological and cultural basis of action and we need, initially, go no further back, where the questions of ethics that concern us are involved. Instead let us see how far this approach can take us.

martino said...

It is not a question of justifying the evaluative premise but having one that exists.
A desire serves such a purpose as in:

P1: Agent A desires that X (prescriptive)
P2: Action Y brings about X (descriptive)
C: A has a reason to Y (the reason being P1).

The Barefoot Bum said...

P1: Agent A desires that X (prescriptive)

This is not a prescriptive premise, it's purely descriptive. There's nothing wrong with this sort of analysis; you're just restating meta-ethical subjective relativism.

(For completeness, I think P1 should read "Agent A all things considered desires that X.")

For example:

P1: Alice desires that Bob be dead
P2: Shooting Bob in the head will cause Bob to be dead
C: Alice has a reason to shoot Bob in the head.

It's kind of hard to see where the prescription is here, again, according to the ordinary meaning of the word.

To make P1 a prescriptive premise (according to the ordinary meaning of the word "prescriptive") you would have to say that "Agent A should desire that X." (Which gets you Alonzo Fyfe's ethical paradigm.)

Of course, you could just be using "prescriptive" in an unusual, idiosyncratic sense, which is not by itself objectionable. However, it would probably be useful to describe why you're using the word in a different sense, and not choosing a different word. Otherwise, you're just doing Humpty Dumpty philosophy or obfuscating that you're stating the obvious.

martino said...

Hi Barefoot

First let me say please keeping reading my posts and providing critical feedback, it is greatly appreciated.

FYI there are a number of posts I need to do to complete this rough draft series fact/value, prescription/description and a summary of why these four are not blockers to ethical naturalism. I am currently trying and to spend one day a week on blog posts, lets see if I can finish this all today and publish them through the week.

Then I will myself critically review the lot and take on board all your criticisms and lets see what the revised versions look like (that I will try and write up next Monday).

Addressing your question here:

P1 is descriptive and prescriptive. Now you are correct that on one meaning of prescriptive there needs to be a should or an ought. Then I would say that P1 is still evaluative and not prescriptive in that sense. It is a statement of an evaluation made by Agent A - to desire that P.

Secondly it say that P1a:"Agent A all things considered desires that X" is unnecessary and possibly misleading. This could imply this is the result of (a) prudential reasoning but, when I write an article on prudence, you will see that I argue how it is dependent upon this more basic formulation (P1 not P1a) to work. Alternatively you could be hinting at something like Griffin's Informed Desire Fulfillment, but that again is going one step too far and this formulation (P1 not P1a) can help with that analysis.

P1 is just stating what Agent A desires, regardless of how they got to that desire.

The Conclusion is a prescription, surely you agree with that? What else can ought or should mean but a "reason to act" I could expand this by saying - maybe I was too brief before
A1: "Ought" means "reason to act".
C1: A has a reason to Y (the reason being P1)
C2: A ought to Y (by A1)

or your version
C1: Alice has a reason to shoot Bob in the head.
C2: Alice ought to shoot Bob in the head (by A1)

Of course none of this is yet "moral" as your version clearly indicates but that was not what I was attempting here, nor what Searle was attempting either. (Anyway I think Searle smuggled in the evaluative premise but that requires an analysis of "promising" which I will need to blog on first before analyzing Searle's version)

Maryann Spikes said...

Our beliefs, moral or otherwise, in order to be knowledge, must be ‘both’ justified (ought) by reasons ‘and’ true (is) to reality, satisfying both Plato and Hume.