The Theory of Relativity and A Priori Knowledge

Introduction

Reichenbach’s habilitation thesis was published in 1920, a year after the eclipse observations that made general relativity famous. It asks what remains of Kant’s synthetic a priori when physics has abandoned Euclidean space and absolute time. His answer separates two things Kant had joined: principles that are necessary for all time, and principles that first constitute the object of physical knowledge by coordinating mathematics with experience. Relativity shows that the second kind can change, so they are a priori only in a relative sense. In correspondence with Moritz Schlick Reichenbach soon replaced this language with talk of conventions; the idea of a “relativised a priori” was taken up again by Michael Friedman in the 1990s.

Connections

Builds on

• On the Electrodynamics of Moving Bodies1905 · Albert Einstein

Criticizes

• Critique of Pure Reason1781 · Immanuel Kant

More works by Hans Reichenbach

• 1938Experience and Prediction