I got back was this ludicrous Marxist gobbledegook. I was disgusted by it, and thought there must be a way back to the defence of western civilization against these things. That's when I became a conservative. I knew I wanted to conserve things rather than pull them down. 1970s–1980s Birkbeck, first marriage Cambridge awarded Scruton his PhD in January 1973 for a thesis titled "Art and imagination, a study in the philosophy of mind", supervised by Michael Tanner and Elizabeth Anscombe. The thesis was the basis of his first book, Art and Imagination (1974). From 1971 he taught philosophy at Birkbeck College, London, which specializes in adult education and holds its classes in the evening. Meanwhile, Laffitte taught French at Putney High School, and the couple lived together in a Harley Street apartment previously occupied by Delia Smith. They married in September 1973 at the Brompton Oratory, a Catholic church in Knightsbridge, and divorced in 1979. Scruton's second book, The Aesthetics of Architecture, was published that year. Scruton said he was the only conservative at Birkbeck, except for the woman who served meals in the Senior Common Room. Working there left Scruton's days free, so he used the time to study law at the Inns of Court School of Law (1974–1976) and was called to the Bar in 1978; he never practised because he was unable to take a year off work to complete a pupillage. In 1974, along with Hugh Fraser, Jonathan Aitken and John Casey, he became a founding member of the Conservative Philosophy Group dining club, which aimed to develop an intellectual basis for conservatism. The historian Hugh Thomas and the philosopher Anthony Quinton attended meetings, as did Margaret Thatcher before she became prime minister. She reportedly said during one meeting in 1975: "The other side have got an ideology they can test their policies against. We must have one as well." According to Scruton, his academic career at Birkbeck was blighted by his conservatism, particularly by his third book, The Meaning of Conservatism (1980), and later by his editorship of the conservative Salisbury Review. He told The Guardian that his colleagues at Birkbeck vilified him over the book. The Marxist philosopher G. A. Cohen of University College London reportedly refused to teach a seminar with Scruton, although they later became friends. He continued teaching at Birkbeck until 1992, first as a lecturer, by 1980 as reader,