Science; possible worlds

Theoretic entity

An entity that is postulated by a scientific theory but cannot be perceived directly.

Scientific Realism

the view that our best scientific theories are (at least approximately) true and that the unobservable entities they posit really exist.

Unobservable entities or phenomena

those items which cannot be observed with the unaided senses but are posited to make sense of what we can observe

Error theory on science

the view that sentences which are ontologically committed to Xs are systematically false - or, at least, we have no good reason to accept any of them as true.

Instrumentalism about science

Although error theory about Xs is true, we need not eliminative discourse about Xs, because the falsity of sentences about Xs is not a problem

Scientific anti-realism

The belief in only the observable entities and phenomena postulated by our best scientific theories.

De re

“about the thing” - modality concerns the modal status of would-be existents

De dicto

“about what is said” - modality concerns the modal status of propositions

Epistemic modality

concerns what is possible, relevant to a given agent’s epistemic perspective.

Deontic modality

concerns what is possible relative to a given set of rules or permissions

Logically possible

if its existence or truth does not entail a contradiction

Nomological (physical) possibility

iff its truth is consistent with the laws of nature

Genuine modal realism

the new that there is a plurality of possible worlds which are just as real as the actual world.

Class nominalism

the view that properties are classes of particular objects. Classes are identical iff they have the same members.

Ersatz (‘fake’) realism

the view that possible worlds can play the same role in an analysis of modality as Lewis’s concrete possible worlds, but taking possible worlds to be an abstract interpretation rather than as concrete

Prefix fictionalism (about possible worlds)

the view that all possible‑worlds talk is really shorthand for an implicit fiction‑prefix—so modal claims are true according to the hypothesis of a plurality of worlds, without committing us to the real existence of those worlds.