Book excerpt: At the end of 2019, Americans were living in an era of post-truth characterized by fake news, weaponized lies, alternative facts, conspiracy theories, magical thinking, and irrationalism. While many complex interconnected factors were at work, this post-truth era was partly the culmination of a cadre of anthropologists and other academics in American universities and colleges during the 1980’s and 1990’s. In Science and Anthropology in a Post-Truth World, H. Sidky examines how their untoward dalliance with problematic and dangerous ideas by Michel Foucault, Jacques Derrida, Jean-François Lyotard, Bruno Latour, and Jean Baudrillard informed and empowered a forceful assault on science and truth in the following decades by corporate organizations, politicians, religious extremists, and right-wing populists.