There must be some sort of logical connection between truth and agreement because to claim that a statement is true is to claim that anyone who disagrees with that statement is mistaken; it is precisely at this point that the truth is objective. To concede that others might disagree without error is to abandon the claim to objectivity and reduce one's utterance to a subjective expression of personal feeling or whim. Now imagine that another person could continue to disagree with one even though he were fully aware of every relevant consideration and fully alive to its logical bearing upon his conclusion. On what ground could one continue to claim truth for one's own statement and insist that the other person must be mistaken? One has no reasons left to advance to the person who already possesses every reason and no logical criticism to show the perfect reasoner that he has drawn the wrong conclusion from these reasons. Thus the claim to truth does presuppose that there would be no disagreement among fully informed and completely rational men. This kind of disagreement, at least, would undermine any claim to objective truth. Let us, then, see what kinds of disagreement there are in ethics and whether any of them compel us to withdraw the claim to truth.
(Carl Wellman, "Ethical Disagreement and Objective Truth," American Philosophical Quarterly 12 [July 1975]: 211-21, at 211)
Note from KBJ: The following propositions are inconsistent:
- If John Rawls and Robert Nozick are fully informed and completely rational, then John Rawls and Robert Nozick agree about distributive justice.
- It is not the case that John Rawls and Robert Nozick agree about distributive justice.
- John Rawls and Robert Nozick are fully informed and completely rational.
Because these propositions are inconsistent, every rational person must reject at least one of them. Wellman and I accept 2. He accepts 1 and therefore rejects 3. I accept 3 and therefore reject 1.
Wellman, by rejecting 3, must believe at least one of the following:
- John Rawls is not fully informed.
- Robert Nozick is not fully informed.
- John Rawls is not completely rational.
- Robert Nozick is not completely rational.
It would be interesting to see which one he believes. Does anyone seriously think that the disagreement between Rawls and Nozick is factual in nature? And if Rawls and Nozick are not completely rational, who is? These are two of the most intelligent human beings who have trod the earth. Let's just say that I find 3 far more plausible than 1. Two fully informed, completely rational individuals can disagree about distributive justice and other evaluative matters.
Keith Burgess-Jackson, J.D., Ph.D. 