Measurement and its instruments

An instrument does not record a bare fact: a thermometer presupposes a whole theory of heat, an apparatus assumes hypotheses about what it captures, and every calibration rests on other measurements, themselves fallible. The precision it displays may thus silently carry forward debatable theories, and exactness become a pretension rather than a fact. How far does a measurement establish the real, rather than already giving it form?

Anchors: Duhem · Bachelard · Koyré