Epistemicism is a theory of vagueness that maintains classical logic and mathematics, asserting that even in cases of vagueness, there is a fact of the matter. For example, in borderline cases like determining if someone is 'tall,' epistemicism claims there is a precise cutoff point, but we are ignorant of it. This ignorance is a distinctive feature of vagueness, not a lack of truth value.
Epistemicism faces challenges in moral contexts because it posits sharp cutoff points for moral truths that are unknowable. This creates a problem for moral guidance, as individuals cannot act on truths they cannot know. Additionally, moral terms like 'permissible' are highly sensitive to usage, leading to semantic plasticity, which complicates the idea of objective moral facts.
Semantic plasticity refers to the high sensitivity of vague terms to slight differences in usage across communities. For example, the word 'tall' might have slightly different meanings in different contexts, leading to different cutoff points. This plasticity makes it impossible for us to know the precise cutoff points, as our beliefs cannot track these subtle differences in usage.
Moral realism, which posits objective moral facts, aligns well with epistemicism's claim that there are sharp cutoff points for moral truths. However, epistemicism's requirement of semantic plasticity for moral terms complicates this alignment, as it suggests that moral terms might pick out slightly different properties in different communities, challenging the idea of a single, objective moral reality.
Epistemicism acknowledges that in borderline moral cases, we cannot know the precise cutoff points for what we ought to do. This creates a tension with the 'ought implies can' principle, which suggests that if we ought to do something, we must be able to know it. However, epistemicism argues that this problem is not unique to it, as any theory of vagueness faces similar challenges in guiding action in borderline cases.
An alternative view is that moral vagueness is not due to vagueness at all but rather to the difficulty of moral questions. Just as in mathematics, where some questions remain unresolved despite precise language, moral questions may be hard to answer without implying that the concepts themselves are vague. This perspective suggests that moral facts exist, but our ignorance stems from the complexity of the issues, not from vagueness.
Sometimes, there is vagueness about whether it is morally permissible (or even in some situations required) to perform a certain act—moral vagueness. What is the source of moral vagueness? Ofra Magidor discusses this topic with Nigel Warburton.
This episode of the Philosophy Bites podcast has been made in association with Vagueness & Ethics), a research project funded by the European Commission (grant agreement number 101028625 — H2020-MSCA-IF-2020) and led by Miguel Dos Santos) at Uppsala University.