D O C . 1 3 1 D I S C U S S I O N O N R E L A T I V I T Y 1 2 9 131. “The Theory of Relativity.” Discussion Remarks at a Meeting of the Société française de Philosophie [Einstein et al. 1922] Dated 6 April 1922 Published July 1922 In: Société française de Philosophie. Bulletin 22 (1922): 91–113. Mr. Einstein. — I just have a word to say about Mr. Hadamard’s remarks. Mr. Hadamard said that a physical theory must first of all be logical, then agree with the experimental findings. I do not believe that this is sufficient and, in any case, this is not evident a priori. To say that a theory is logical means that it is built of symbols that are linked among themselves by means of certain rules and to say that theory is in conformity with experience means that one possesses rules of corre- spondence between these symbols and the findings. Relativity arose out of experi- mental necessity this theory is logical in the sense that one can give it deductive form, but clear rules that make its elements correspond to reality still need to be known thus there are three postulates, not two, as Mr. Hadamard thought. [. . .] Mr. Einstein. — Which tensor is that? [. . .] Mr. Einstein. — Geometry is an arbitrary conception one is always free to adopt the one one wants, in particular, a Euclidean geometry but Euclidean con- cepts do not have any physical meaning and cannot serve us physicists. Moreover, the relation between the real continuum and imagined geometrical space is not uni- vocal and one cannot say that one manner of speaking is preferable to another. [. . .] Mr. Einstein. — One can always choose the representation one wishes if one believes it is more convenient than another for the task one proposes to undertake but it has no objective meaning. [. . .] [p. 97] [p. 98] [p. 99]