Mellenbergh Lecture: Eran Tal

Measurement and the Riddle of Factuality

On the 12th of June 11:00-12:00, Eran Tal will give the next Mellenbergh Lecture in REC C0.02. Eran Tal is professor in the philosophy of science at McGill University. He is among the primary authorities on the philosophy of measurement, and has worked on various topic in physics and the social sciences; his recent analysis of the function of theory in the construction of measurement instruments stands out as a landmark paper in this area.

Measurement is taken to provide knowledge of the way things are, and not merely of the way things would or could be under some specified set of conditions. In this regard, measurement is epistemically distinct from other forms of quantitative estimation, such as prediction and calculation. Nonetheless, measurement depends on theoretical and statistical assumptions and on idealized models that are themselves only testable through further measurements. This introduces a threat of infinite regress against attempts to justify the factual status of measurement results. This paper offers a new analysis and resolution to the riddle of factuality. I consider and reject three existing accounts of factuality in measurement: empiricist, information-theoretic, and causal. I then propose an alternative, pragmatist kind of response to the riddle of factuality. According to the pragmatist solution, the presentation of measurement results as factual statements is a pragmatic choice. This choice is justified, not by any special ability of measurement to detect and isolate empirical structures, signals, or causes, but by the convenience of expressing knowledge claims in the most modular way that is fit for the purpose at hand.