Major challenges for ethics include the fact / value distinction, the error theory which seems to undermine the reality of moral claims and apparent relativism across cultures and eras.
12.
The second form, which one might call the " presupposition failure " form of error theory, claims that moral beliefs and assertions are not true because they are neither true nor false.
13.
In the late 1970s, mathematician Ian McKiggan developed his theory of exponential longitude error theory to explain discrepancies, McIntyre's own theory about distortion of the maps and the calculations used to correct the maps has also been challenged.
14.
A more moderate position such as J . L . Mackie's " error theory " suggests that false beliefs should be stripped away from a mental concept without eliminating the concept itself, the legitimate core meaning being left intact.
15.
The first, which one might call the " global falsity " form of error theory, claims that moral beliefs and assertions are false in that they " claim " that certain moral facts exist that in fact do not exist.
16.
Because expressivism claims that the function of moral language is not descriptive, it allows the irrealist to avoid an error theory : the view that ordinary moral thought and discourse is committed to deep and pervasive error, and that all moral statements make false ontological claims.
17.
This has in recent years developed as a recognised category proceeding from the work of Hume, G . E . Moore and the error theories of J . L . Mackie who seeks a real basis, if any, for talk of values and right and wrong.
18.
Ethical subjectivism stands in opposition to moral realism, which claims that moral propositions refer to objective facts, independent of human opinion; to error theory, which denies that any moral propositions are true in any sense; and to non-cognitivism, which denies that moral sentences express propositions at all.
19.
Cognitivism is so broad a thesis that it encompasses ( among other views ) moral realism ( which claims that ethical sentences express propositions about mind-independent facts of the world ), moral subjectivism ( which claims that ethical sentences express propositions about peoples'attitudes or opinions ), and error theory ( which claims that ethical sentences express propositions, but that they are all false, whatever their nature ).
