In the eighteen years since Ivan Illich’s death, David Cayley has been reflecting on the meaning of his friend and teacher’s life and work. Now, in Ivan Illich: An Intellectual Journey, he presents Illich’s body of thought, locating it in its own time and retrieving its relevance for ours. Ivan Illich (1926–2002) was a revolutionary figure in the Roman Catholic Church and in the wider field of cultural criticism that began to take shape in the 1960s. His advocacy of a new, de-clericalized church and his opposition to American missionary programs in Latin America, which he saw as reactionary and imperialist, brought him into conflict with the Vatican and led him to withdraw from direct service to the church in 1969. His institutional critiques of the 1970s, from Deschooling Society to Medical Nemesis, promoted what he called institutional or cultural revolution. The last twenty years of his life were occupied with developing his theory of modernity as an extension of church history.