Abstract

I argue that technological functions warrant specific epistemological attention, which they have not received thus far. From a user’s perspective, knowledge about the possible functions of an artefact is not provided exclusively by beliefs about its physical characteristics; it is primarily provided by know-how related to its use. Analysing the latter shows that standards of practical and not just theoretical reasoning are involved. Moreover, knowledge of the function of artefacts is primarily based on testimony and a social division of labour with respect to rational artefact use. Combining these two features, knowledge of functions can be shown to create a rich normative context, manifest in notions such as ‘improper’ use: designers inform users about how they ought to use artefacts. This normativity in knowledge of functions, which takes a different shape for possible and proper functions, is lacking in standard, descriptive knowledge.Keywords: Epistemology; Function; Knowing-how; Testimony; Artefact; Practical rationality.