Martin Heidegger’s 1925-26 lectures on truth and time provided much of the basis for his momentous work, Being and Time. Not published until 1976 as volume 21 of the Complete Works, three months before Heidegger’s death, this work is central to Heidegger’s overall project of reinterpreting Western thought in terms of time and truth. The text shows the degree to which Aristotle underlies Heidegger’s hermeneutical theory of meaning. It also contains Heidegger’s first published critique of Husserl and takes major steps toward establishing the temporal bases of logic and truth. Thomas Sheehan’s elegant and insightful translation offers English-speaking readers access to this fundamental text for the first time.