Past exam of the philosophy of science supplementary subject of the University of Oxford / 2018 / 5

Logical empiricism seeks to preserve the authority of logic and mathematics while denying that they supply unsupported factual discoveries about nature. The analytic-synthetic distinction offers a division of labour: an analytic truth holds by logical or linguistic rules, whereas a synthetic truth requires information about the world. A logical implication can organize a physical calculation without deciding that its premises describe an actual apparatus.

Without some such account, a strict claim that all genuine knowledge is empirical faces its own treatment of logic and mathematics. A logical tautology is not usually established by sampling cases. Conversely, a measurement of a wire's length does not follow merely from fixing the meaning of “metre”. The distinction lets the empiricist use formal structure while locating factual risk in the empirical application. This does not mean that every historical version of logical empiricism accepted the same sharp boundary.

The central challenge is to explain analyticity without a circle. Calling a statement true by meaning appeals to a notion that must itself be clarified. Defining the relevant meanings by synonymy, then explaining synonymy through analytic equivalence, gives no independent foundation. Willard Van Orman Quine develops this pressure against definitions, substitution tests and rules, and links it to the testing of whole theoretical packages.^[ref]

A useful reply distinguishes describing ordinary language from constructing an explicit formal framework. Rudolf Carnap's meaning postulates restrict the admitted interpretations of a language. One can define a sentence as analytic relative to those rules when it holds under every permitted interpretation.^[ref] That is a precise and usable local classification. It does not, merely by stipulation, prove that a natural-language sentence was already analytic independently of the framework, or that a scientific framework can never be revised.

Thus a modest defence is more convincing than an absolute one. Logical empiricists can justify a distinction relative to stated linguistic and inferential commitments, using it to separate a model's formal consequences from empirical assumptions. They have a harder task if they require a unique, unrevisable division governing all meaningful discourse. The practical value of explicit conventions survives even if there is no universal boundary immune to scientific and linguistic change.