Twenty-one cards and letters from Frege to Wittgenstein—the totality of the correspondence between them presently known to exist—were discovered in 1988, long after elaborate and far-reaching interpretive traditions had grown up around each philosopher.1 It is unlikely that these missives will of themselves radically reshape our understanding of either. But for historians of logic and analytic philosophy, as well as for anyone interested in German and Austrian intellectual history at the time of the First World War—and especially Wittgenstein’s and Frege’s places within it—these are significant and interesting documents.