Expressivist like Blackburn like to invoke deflationary accounts of truth as a way to save the common sense intuition that moral judgements can be straightforwardly true or false. I have elsewhere argued that this strategy fails to absolve the espressivist from giving an account of justification and, without some kind of modification, the expressivist is committed to relativism. Blackburn’s expressivism collapses into pure autobiography.
Here is another way to make the argument. Take the following claim: Eating meat is immoral. According to the deflationist this will be true just in case eating meat is immoral. This can be put in terms of the T-Schema as so,
“Eating meat is immoral’ is true if and only if eating meat is immoral
But what are to make of the right hand side of this bi-conditional? We cannot take it as naming some fact according to the expressivist. It seems we must, then, give it the expressivist meaning. Doing so yeilds the B-schema
“Eating meat is immoral’ is true if and only if Boo eating meat
This makes it clear that deflationsim about truth cannot help the Blackburns of the world avoid giving a real theory of moral justification.
Or is there some other interpretationof the right hand side of the bi-conditional?