Thomas Reid's Argument against Moral Non-Cognitivism
In Thomas Reid's Essays on the Active Powers of Man, he presents a compelling argument against Hume's moral theory. As I understand Reid's criticism of Hume, this argument may have some relevance on contemporary ethics regarding whether moral claims are cognitive or non-cognitive (if unfamiliar with this issue read this). Reid argues that moral claims must have a cognitive basis. Reid's argument is essential linguistic. He compares the following two claims:
(1) “That man did well and worthily, his conduct is highly approvable”If moral non-cognitivism is true, then these two statements should mean the same thing. But Reid points out that these two statements do not mean the same thing. Reid explains, “The first expresses plainly an opinion or judgment of the conduct of the man, but says nothing of the speaker. The second only testifies a fact concerning the speaker—to wit, that he had such a feeling.”
(2) “The man’s conduct gave me a very agreeable feeling.”
Reid extends his argument by showing that the contradictories of (1) and (2) also have different meanings, which reinforces his point that (1) and (2) have different meanings. When people hold contradictories over (1), they have a disagreement over a judgment. Whereas when people disagree concerning (2), this results in a personal affront. “[F]or, as every man must know his own feelings,” writes Reid, “to deny that a man had a feeling which affirms he had, is to charge him with falsehood.”
I believe Reid's strategy is instructive. The burden rests on non-cognitivists to find a plausible harmonization of (1) and (2), or to show that (1) is meaningless. Since I find neither of these solutions plausible, I believe Reid's criticism demonstrates a key problem with moral non-cognitivism.