That Heidegger should devote a formal study to λόγος in Heraclitus is not at all surprising.¹ What is surprising is that it took him so long to do so. The indices in EM were, after all, only incidental to another problematic and deserved elaboration for themselves. The fact is that the problem of λόγος has been with him since the beginning, if only under the guise of "logic." We have only to look at the list of the author's lecture courses and seminars at Freiburg to realize how frequently he recurred to the theme.²