Frege, who was turning sixty-three in November 1911, was visited that fall by a twenty-two-year-old Austrian who was neglecting his studies in aeronautical engineering at the University of Manchester. While studying aeronautics, Ludwig Wittgenstein had become interested in the nature of mathematical proof, which led him to Russell's Principles of Mathematics. In this book Russell aimed to popularize the project he and Whitehead pursued in the Principia Mathematica, namely to show that mathematics is reducible to a few logical principles. The Principles also contained something new, namely an appendix devoted to “The Logical and Arithmetical Doctrines of Frege” (Russell 1903). While the Principles were being prepared for print, Russell discovered that Frege had already devoted a lifetime of work to the project of logicism, and so he decided quickly to study Frege's work and write an appendix for the book. This appendix brought Frege's neglected work into the limelight and to the attention of Wittgenstein.
Little is known about Wittgenstein's visit in Jena except Wittgenstein's comment that Frege “wiped the floor” with him. Frege recommended that Wittgenstein return to England and study with Russell at Cambridge University, which he did. Nevertheless, Frege and his works left a lasting impression on Wittgenstein, as Wittgenstein himself suggests in the preface to the Tractatus Logico-Philosophicus, published ten years after his meeting with Frege, when he writes, “I am indebted to Frege's magnificent [Großartig] works.”