Protocol statements, physicalism, and metadata: Otto Neurath on scientific evidence

Otto Neurath's role in the so-called protocol sentence debates is typically framed as primarily an epistemologically radical rejection of empiricist foundationalism. However, less well recognized is that from this debate, Neurath emerges with a conception of protocol statements that functions as a radical reconceptualization of evidence. Whilst recognizably still empiricist, Neurath's conception of evidence breaks with many of the key assumptions that predominate within the empiricist tradition. In rejecting the assumption of an epistemologically privileged relationship between an observer and their own observation reports, Neurath shifts the emphasis onto the importance of contextualizing information that guarantees the stability of observation reports. In so doing, he not only provides a conception of evidence better suited to the actual role of evidence in science, but also anticipates contemporary discussion of the importance of evidential metadata.