I took Chris’s meaning to be that moral realism (as defined by the SEP) says that moral claims are fact claims possessing truth values but says nothing about the discoverability or computability of those truth values. Your definition would have every moral realist insisting that every moral claim can be proven either true or false, but it seems to me that Chris’ definition allows moral realists to leave open Gödel-incompleteness status for moral claims, considering their truth or falsity to exist but be possibly incomputable, and still be moral realists. Or, to take no position on whether rational minds would come to the truth values of moral claims, only on whether the truth values existed. Your definition would exclude both of those from moral realism.
Chris, please correct me if this is not what you meant.
I have no problem with Godel-incompleteness, uncomputability, and so on in a system that allows you to state any moral proposition.
However: if a moral realist believes that “moral claims are fact claims possessing truth values”, then what does he belief regarding the proposition (1) “there exists at least one moral claim that can be proven true or false”? (Leaving aside claims that simply induce contradictions, are not well defined, etc.)
If he thinks such a claim exists, that is the same as saying there is a Universally Compelling Argument for or against that claim. And that is a logical impossibility. I can always construct a mind that is immune to any particular argument.
If he thinks no such claims exist, then it seems to be a kind of dualism—postulating a property “truth” of moral claims, which is not causally entangled with the physical world. It also seems pointless—why care about it if no actual mind can ever discover such truths?
ETA: talking about ‘proving’ claims true or false is a simplification. In reality we have degrees of beliefs in the truth-value of claims. But my point is that moral-realistic claims seem to be disengaged from reality; substitute “provide evidence for” in place of “prove” and my argument should still work.
I took Chris’s meaning to be that moral realism (as defined by the SEP) says that moral claims are fact claims possessing truth values but says nothing about the discoverability or computability of those truth values. Your definition would have every moral realist insisting that every moral claim can be proven either true or false, but it seems to me that Chris’ definition allows moral realists to leave open Gödel-incompleteness status for moral claims, considering their truth or falsity to exist but be possibly incomputable, and still be moral realists. Or, to take no position on whether rational minds would come to the truth values of moral claims, only on whether the truth values existed. Your definition would exclude both of those from moral realism.
Chris, please correct me if this is not what you meant.
I have no problem with Godel-incompleteness, uncomputability, and so on in a system that allows you to state any moral proposition.
However: if a moral realist believes that “moral claims are fact claims possessing truth values”, then what does he belief regarding the proposition (1) “there exists at least one moral claim that can be proven true or false”? (Leaving aside claims that simply induce contradictions, are not well defined, etc.)
If he thinks such a claim exists, that is the same as saying there is a Universally Compelling Argument for or against that claim. And that is a logical impossibility. I can always construct a mind that is immune to any particular argument.
If he thinks no such claims exist, then it seems to be a kind of dualism—postulating a property “truth” of moral claims, which is not causally entangled with the physical world. It also seems pointless—why care about it if no actual mind can ever discover such truths?
ETA: talking about ‘proving’ claims true or false is a simplification. In reality we have degrees of beliefs in the truth-value of claims. But my point is that moral-realistic claims seem to be disengaged from reality; substitute “provide evidence for” in place of “prove” and my argument should still work.