Sketches as Mental Reifications of Theoretical Scientific Treatment

Abstract

Sketches are used abundantly in the practice of science. The purposes for which they are used are diverse, such as illustration, exemplification or data display. Moreover, sketches in science can be of very different things — from concrete objects to abstract conceptions. The graph of a mathematical function is very different in what it shows from a drawing of an experimental set-up or from an X-ray picture. My focus, in this paper, is on a quite specific use of sketches: sketches that stand for the theoretical treatment of empirical phenomena;’ they function as substitutes for the physical processes (and their theoretical description) that are thought to produce these phenomena. Examples for such sketches will be given below. Relying on conventions old and new, the point is that theoretical information — abstract theories from physics as they are applied to an empirical phenomenon — is put into pictures. This means that, in effect, abstract and theoretical conceptions about the empirical world, mostly expressed in mathematical formulae, are reified, i.e. “made into a thing”.² By being put into a picture, scientific treatment dominated by theoretical conceptions is effectively made into two-dimensional objects.