Upon finishing his Ph. . D in philosophy at Humboldt University of Berlin in 1986 , he joined the faculty of Bir Zeit University , . He was in charge of the Philosophy and Cultural Studies Department for two years , from 1994 to 1996 . Upon completing his Ph. . D in philosophy at Humboldt University of Berlin ( then East Germany ) in 1986 , he joined the faculty of Bir Zeit University , and went on to head the Philosophy and Cultural Studies Department for two years , from 1994 to 1996 .