Pierre Hadot (1922–2010), professor of ancient philosophy at the Collège de France, published, in the late 1950s and early 1960s, some of the earliest work on Wittgenstein to appear in French. Hadot conceived of philosophy as an activity rather than a body of doctrines and found in Wittgenstein a fruitful point of departure for ethical reflection. Hadot's understanding of philosophy as a spiritual exercise — articulated through his reading of ancient philosophy but also the American transcendentalists Henry David Thoreau and Ralph Waldo Emerson — will find an echo in Wittgenstinian thinkers such as Stanley Cavell and Cora Diamond. Ultimately philosophy for Hadot is a call to personal and political transformation.