Indeterminacy

Indeterminacy

Two types of indeterminacy have been propounded: ontological and semantic. I am referring to physics and linguistics—quantum-theoretic indeterminacy and Quine’s indeterminacy of translation. These indeterminacy theses are opposites of each other in the sense that indeterminacy of meaning presupposes determinacy of reality, while indeterminacy of physical reality contrasts with an assumed determinacy of meaning. There is a fact of the matter about whether a rabbit is the same as an undetached rabbit part; it is not, and the argument for the indeterminacy of the meaning of “rabbit” assumes this. On the other hand, quantum indeterminacy as to position does not question the determinacy of meaning of “Particle p is in position x”; no one thinks that statement is indeterminate as to what it says. In the former case, the objective facts are determinate—there is a fact of the matter about whether an object is a rabbit or an undetached rabbit part—while in the latter case the language is determinate, but the physical reality is not. It is assumed in both cases that the determinacy of one realm does not carry over to other: determinacy of fact does not entail determinacy of meaning, and determinacy of meaning does not entail determinacy of fact. The two realms are taken to be separable and insulated. Determinacy of meaning is possible in an indeterminate physical world, and determinacy of reality does not entail determinacy of meaning.

This will strike a certain kind of externalist as odd: why don’t the facts determine the meanings? In a determinate world, meaning will be determinate, while in an indeterminate world meaning will be indeterminate. We normally take both to be determinate, so no clash appears; but if we have a combination of determinate and indeterminate, we must assume insulation—world and mind don’t line up. What if both were indeterminate—Quinean quantum theory? Then there is no mismatch: the world is as indeterminate as meaning and vice versa. The two fit each other like a glove; neither is misleading as to the other. The particle has no determinate position, and no sentence determinately says it does; and the meaning of “rabbit” is indeterminate, and the reality of rabbits does not disagree. It’s indeterminacy all the way down (or up). But the mixed position has questions to answer about the relation between language and reality: how can facts be distinct and yet words about them can’t differ in meaning; and how can language differentiate between particle positions, but particles cannot? If the world is fuzzy, how come language is so precise; and if the world is sharp, why is language so fuzzy? It seems paradoxical. One would think they would track each other.

There is a way out: go epistemic. We don’t know the meaning of “rabbit”, and we don’t know the position of particles—though there is a determinate fact of the matter in both cases. That was our position all along. The commonsense view is that we can’t decide the motion of particles and we can’t look into the native’s mind, so these facts are epistemically indeterminate; but there is no ontological indeterminacy, no objective fuzziness. Meaning and world match up, but they are both inaccessible in their fine structure. Physical reality is determinate and so is psychological reality. The facts fix the meanings, and the meanings fix the facts.