His first book, Words and Things (1958) prompted a leader in The Times and a month-long correspondence on its letters page over his attack on linguistic philosophy. As the Professor of Philosophy, Logic and Scientific Method at the London School of Economics for 22 years, the William Wyse Professor of Social Anthropology at the University of Cambridge for eight, and finally as head of the new Centre for the Study of Nationalism in Prague, Gellner fought all his life—in his writing, his teaching, and through his political activism—against what he saw as closed systems of thought, particularly communism, psychoanalysis, relativism, and the dictatorship of the free market.