According to Alain Badiou, truth’s existence is not dependent upon philosophy because philosophy itself is not a creator of truth. Badiouan thought submits philosophy to the universe of truth through the mediation of truth procedures. Badiou names these procedures love, politics, art and science. In contrast, the instinctual reason of democratic materialism, which Badiou defines as the partnership between parliamentary democracy and neo-liberal pragmatism, replaces love with physical beauty, politics with technical power, art with a marketable talent and science with (...) a competitive genius. These replacements also correspond to post-truth. This article contrasts the concept of “disinterested interest” in Badiou’s truth procedures with “self-interest” reigning over democratic materialism’s reality procedures. Following Badiou, I explain how “self-interested interest” reproduces the human-animal’s instinctual reason, which triggers post-truth politics. Commitment to truth in a post-truth era therefore cannot be sustained by appealing to democratic materialism’s manipulated knowledge but must be guided by disinterested interest. The article argues that knowledge cannot be an antidote to post-truth because democratic materialism often uses knowledge as an instrument or sometimes as a control mechanism, to strengthen the position of post-truth in many circumstances. (shrink)