Abstract

Roy Wood Sellars (1880–1973) is often reduced to his role as father of Wilfrid Sellars. This is unfair because during the 1920s, ‘30s, and ‘40s, Roy Wood was one of the leading figures of the then prevailing American realist movement. In the present paper, I will focus on one particular facet of R. W. Sellars’ philosophical approach: his continual examination of Albert Einstein’s special theory of relativity. I shall primarily reconstruct his discussion of Einstein’s theory, as it can be found in his seminal The Philosophy of Physical Realism (1932). In contrast to authors such as Bertrand Russell or Émile Meyerson, Sellars refused to interpret special relativity in a realist vein. In his view, it should be seen as an “ars mensurandi” and thus being interpreted purely operationally. As with Einstein himself, the concept of simultaneity was his paradigm case in point. However, Sellars opined that besides the physical (mensurational) concepts of time and simultaneity there also exists an ontological understanding of these notions. “Real” time and “absolute” simultaneity are, according to Sellars, the indispensable non-relativistic counterparts to Einstein’s respective relativistic conceptions. They are to be interpreted realistically since they prove, Sellars maintains, to be explanatory regarding events in Einstein-Minkowski’s world. In the course of the paper, I shall compare this view with the one defended by Henri Bergson. Furthermore, Sellars’ later approach from the 1940s and ‘50s will be briefly considered and critically discussed by confronting it with more recent attempts at ontologically ‘grounding’ special relativistic kinematics.