Book excerpt: Human Life in Motion presents for the first time the previously unpublished transcripts of the seminars on Aristotle Martin Heidegger gave in the 1920s. These transcripts reveal much about the evolution of his thought during that time. Detailed student transcripts for these seminars appear among the papers of one of Heidegger's students, Helene Weiss, held today in the Special Collections Department of Stanford University. Analyzing and organizing hundreds of pages of these transcripts written by different students, Francisco Gonzalez brilliantly reconstructs the original seminars. He summarizes what Heidegger presented and claimed in each class. Gonzalez also throws into relief the overarching philosophical significance of the seminars, showing how the different interpretative moves or claims are connected and where they lead, something which in turn requires explicating them in the context of both the Aristotelian texts discussed and Heidegger's own thought during this period. Essential reading for students and scholars of Heidegger or Aristotle, Human Life in Motion is a publishing event that forces a reconsideration of the thought and legacy of both philosophers.