In the 1960s, Sviták was one of Czechoslovakia's most vocal advocates of democratic socialism (a distinction he shared with Karel Kosík, Czechoslovakia's other prominent Marxist humanist philosopher). After the Warsaw Pact invasion of Czechoslovakia in August 1968, Sviták was stripped of his citizenship and sentenced to a lengthy jail term. Instead of serving the jail term, he chose to emigrate, first to New York City and in 1970 to Chico, California, where he was offered an academic position. Sviták worked at Cal State Chico until 1990, when he returned to Czechoslovakia after the end of Communist Party rule. In the early 1990s Sviták remained a staunch proponent of democratic socialism, turning his critical pen to the new, post-Communist regime. He died in Prague in 1994.