One thing I'm having problems with in understanding UPB is the meaning of Universally Preferable Behaviour, and how it handles the is/ought dichotomy. The book says about Humes argument, "It is impossible to derive an ought from an is [...] It is true that if a man does not eat, he wil die -- we cannot logically derive from that fact a binding principle that he ought to eat. If he wants to live, then he must eat. However his choice to live or not remains his own." *, and of UPB, "Ethics as a discipline can be defined as any theory regarding preferable behaviour that is universal, objective, consistent -- and binding. Naturally, preferential behaviour can only be binding if the goal is desired. If I say that is is preferable for human beings to exercise and eat well, I am not saying that human beings must not sit on the couch and eat potato chips. What I am saying is that if you want to be healthy, you should exercise and eat well."
What I get from this is that it's acceptable to say that "x is required for y", but not that someone "should do x" unless they prefer y, and a UPB-statement is simply saying that a person must do an x if they want a y. However in the next chapters on Preferences and Universally Preferable Behaviour, the book seems to suggest that UPB statements can exist without tagging on an "if you prefer y" statement. Stef says "when I talk about universal preferences I am talking about what people should prefer not what they always do prefer." That's ok if you interpret it to mean "what people should prefer given they have certain goals," but then Premise 4 for arguments about universality attempts to prove "that truth is universally preferable to error," which does not have any "for y" statement tagged on.
The argument for Premise 4 goes:
If you correct me on an error that I have made you are implicitly accepting the fact that it would be better for me to correct my error. Your preference for me to correct my error is not subjective, but objective and universal.
You don't say to me: "You should change your opinion to mine because I would prefer it," but rather: "You should correct your opinion because it is objectively incorrect." My error does not arise from merely disagreeing with you, but as a result of my deviance from an objective standard of truth. Your argument that I should correct my false opinion rests on the objective value of truth -- i.e. that truth is universally preferable to error, and that truth is universally objective.
So if I make the argument that "UPB is invalid", I am implicitely saying: "You should not say UPB is valid", "You should not say UPB is valid because that's not true", and "You should not say UPB is valid because that's not true and telling the truth is universally preferable."
Then we turn to Premise 6 (p57):
If I tell you that the world is flat and you reply that the world is not flat, but round, then you are implicitly accepting the axiom that truth and falsehood both exist objectively, and that truth is better than falsehood.
If I tell you that I like chocolate ice cream, and you tell me that you likevanilla, it is impossible to "prove" that vanilla is objectively better than chocolate. The moment that you correct me with reference to objective facts, you are accepting that objective facts exist, and that objective truth is universally preferable to subjective error.
That would be to argue that because I said "you should tell the truth because telling the truth is universally preferable", and any possible argument makes that claim, we can derive that "truth is universally preferable to error," or that "people should prefer truth". Doesn't that violate the is/ought rule? The claim is that "to argue objective facts one must prefer truth to error, therefor one must prefer truth to error."
Likewise, Premise 4 says that correcting someone on an error implies that it is better to correct an error, but I don't think this can be expanded to say "correcting errors is always better than not correcting errors," only "correcting errors is better than not correcting errors in this conversation."
In the next chapter Stef gives five proofs of UPB, for the same reason these two premises fail, I think proofs one two and five don't add up either. I'm not sure about proofs three or four.
The second sylogism in proof 1 would read:
Arguing against the validity of universally preferable behaviour demonstrates preferable behaviour for debating.
And the first syllogism in the second proof would be:
All organisms require preferable behaviour for life to live.
And the first in proof 5 would be:
Organisms succeed by acting upon preferable behaviour for reproduction.
I do think I have the right definition of UPB, the later chapters talk about, for example, not rapeing being UPB and not murdering being UPB, instead of not raping being UPB for x, or not murdering being UPB for x. I'm just not seeing how it's possible that something can be UPB without having the for clause, and still conform to the is/ought rule.
Have I made a mistake somewhere or am I misunderstanding the arguments? Help would be appreciated, I'm not ready to give up and become a moral subjectivist just yet :)
* Sorry about the quotes, there used to be page numbers there but I looked at my printout of the book and somehow the page numbers on my printout aren't the same as the pdf on the web site, and I'm running out of time for this post, so I think it's better to have no page numbers than to give you the wrong ones :)