was a professor of Psychology at the University of Amsterdam from 1956 to 1992 and subsequently extraordinary professor of Emotional Theory at the same institution, untill 2002. In 2003 he taught as a honorary fellow at the University College of the Utrecht University. He wrote – among other things - Post uit Friesland (1984), De emoties (1988), De psychologie heeft zin (1993) and The Laws of Emotion (2006).