Analysis of a Conversation on the Sheffer Stroke and WF Schemes between Bertrand Russell and Ludwig Wittgenstein in April 1913

The chapter offers a reconstruction of a possible conversation between Russell and Wittgenstein about truth-tables and the Sheffer Stroke on the basis of jottings in Russell’s and Wittgenstein’s handwriting on folio 1v of Russell’s paper ‘Matter – The Problem Stated’. A direct comparison with Wittgenstein’s Notes on Logic and preserved letters in the Bertrand Russell Archives suggests 23 April 1913 as the most likely date for such a conversation. In conclusion, it can be assumed that Wittgenstein developed and used truth-tables at that time, but considered them to be of secondary importance for logic compared to the ab-functions and ab-diagrams developed at the same time. The chapter also presents a facsimile picture of folio 1v.