 In 1947, Merleau-Ponty participated regularly in the Collège philosophique, an association formed by Jean Wahl to provide an open venue for intellectual exchange without the academic formality of the Sorbonne, and frequented by many leading Parisian thinkers. Merleau-Ponty published his first book of political philosophy in 1947, Humanisme et terreur, essai sur le problème communiste [Humanism and Terror: An Essay on the Communist Problem, 1969, HT], in which he responded to the developing opposition between liberal democracies and communism by cautioning a “wait-and-see” attitude toward Marxism. A collection of essays concerning the arts, philosophy, and politics, Sens et non-sense [Sense and Non-Sense, 1996b/1964], appeared in 1948. In the fall of 1948, Merleau-Ponty delivered a series of seven weekly lectures on French national radio that were subsequently published as Causeries 1948 (2002/2004).