Moral Error Theory

Unlike Moral Non-Cognitivism, Moral Error Theory recognizes that people intend to make fact claims when making moral propositions (Such as "murder is evil"). Moral Error Theory only claims that those fact claims are in error for one or more reasons. However, like Non-cognitivists error-theorists also rely on certain semantic claims about what people mean by moral propositions that don't hold up in practice, and suffer from other underlying theoretical problems and burden-of-proof issues.

Absolute Error

This is the typical form of error theory, absolute error as explained here is the belief in error theory that the error is absolute rather than probabilistic due to unknowable circumstance. That is that the error occurs due to an impossibility of the claim.

The typical assumption of error theorists is that morality is purely opinion, so any statement of objective fact about morality is in error due to the claimed subjectivity of morality. The assumption there is that people mistake their opinions for objective fact. In accordance with the assumption of subjective morality the same way it would be an error to say "chocolate is delicious" in an objective sense it would be an error to say "Murder is wrong" in the same sense.

A simple retort to this assumption of error theorists is that they are begging the question by assuming morality is subjective without making an argument. Error theorists usually do so on the basis of a straw-man of objective morality.

This straw man is to assume, in the case of those assertions of objective truth to morality, that people are talking about a metaphysical substance of sin or evil of a supernatural nature that can not exist (or is believed to be impossible), rather than a principle of some other kind that can be factually assessed.

This mistake may be understandable for non-theistic error theories, and particularly those identifying as "new atheists" because theists apologists advocate for this same error: asserting that the only possible source of objective morality is supernatural (and thereby god).

Where the theist apologist would argue "(objective) Morality exists therefore god must exists" the atheist error theorist would argue "God does not exist therefore (objective) morality does not exist"

The fundamental problem with this reasoning is that it ignores systems of objective morality based on principles from which expressions can be evaluated as true or false. A popular example is utilitarianism, where science can determine which actions have more or less utility and express this in objective terms. The error theorist can try to argue that this is not what people mean by morality, but IF this is what a person means by morality or what people mean generally by morality then the error theorist must accept defeat or turn to attack science and reason:

Probability Error

This is the less common form of error theory which derives from the same reasoning of radical skepticism of science and logic: the argument goes that because we can not know anything with certainty then we can not know anything at all and are just guessing, and that any guess is as good as another so the claim that one thing or another is more likely morally right or wrong is in error.