Max Horkheimer is well known as the director of the Frankfurt Institute for Social Research and as a sometime collaborator with Theodor Adorno, especially on their classic "Dialectic of Enlightenment". These essays reveal another side of Horkheimer, focusing on his contributions to critical theory in the 1930s. Included are Horkheimer's inaugural address as director of the Institute, in which he outlines the interdisciplinary research programme that would dominate the initial phase of the Frankfurt School; his first full monograph; and a number of other pieces published in the 1930s. The essays, most of which have not appeared in English before, are surprisingly relevant to current postphilosophy debates, notably, "On the Problem of Truth", with its focus on pragmatism, and "The Rationalism Debate in Current Philosophy", a sustained critique of the post-Cartesian philosophy of consciousness. There are also essays relevant to the current foundations debate within Contintenal philosophy. And the question of rationality versus relativism is sustained throughout the volume.