On September 13, 1918, as autumn settled upon the Western Front after the costly failure of Ludendorff’s Spring Offensive and ensuing loss of strategic initiative against strengthening Allied Armies, Martin Heidegger, serving in a weather unit in the vicinity of Verdun, sat down in the early morning at his observation post to write a letter to his recently betrothed Elfriede, at home in Freiburg with their newborn son. He is sitting “at the telephone and passing huge quantities of numbers on to the artillery, airship men, [and] gas officers” against the backdrop of “heavy artillery” and the “thunder of bombs, making everything in the hut shake.”