Uncertainty involves not knowing a fact that exists, such as not knowing how a bank will invest money. Indeterminacy, however, refers to situations where there is no clear fact of the matter, such as borderline cases where it's unclear whether a pile of stones constitutes a heap or whether a color is yellow or red.
Timothy Williamson argues that what appears to be indeterminacy is actually ignorance of a precise fact. He believes that classical logic, which states that every meaningful proposition is either true or false, should not be abandoned. This view maintains that there is always a fact of the matter, even if we cannot determine it, preserving the simplicity and success of classical theories.
Degrees of truth introduce the idea that propositions can be partially true, such as being 0.75 true, rather than strictly true or false. This challenges classical logic, which relies on binary truth values, and requires revising theories of truth, logic, and rational decision-making to accommodate intermediate truth values.
If indeterminacy is treated as uncertainty, there is a fact of the matter about when a fetus becomes a person, but we are ignorant of it. If indeterminacy is genuine, there may be no clear fact, making moral decisions more complex. For example, destroying a cluster of cells might be analogous to blowing up a house without knowing if someone is inside, raising ethical dilemmas.
One alternative is the idea of multiple classical interpretations of language, where borderline cases arise from disagreements between interpretations. Another is the concept of degrees of truth, where propositions can have intermediate truth values. Both approaches aim to preserve the idea of indeterminacy without collapsing it into mere uncertainty.
Linguistic conventions settle clear cases, such as what is definitively yellow or not yellow, but leave borderline cases open. Indeterminacy arises when multiple interpretations of language disagree on how to classify these borderline cases, even though each interpretation adheres to classical logic.
How can we make decisions under conditions of indeterminacy? Robert Williams discusses this challenging issue 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.