Hungarian psychologist Mihaly Csikszentmihalyi was the Distinguished Professor of Psychology and Management at Claremont Graduate University. He is noted for his work in the study of happiness and creativity, but is best known as the architect of the notion of flow, a highly focused mental state.
Martin Seligman, former president of the American Psychological Association, described Csikszentmihalyi as the world's leading researcher on positive psychology.
Csikszentmihalyi once said: "Repression is not the way to virtue. When people restrain themselves out of fear, their lives are by necessity diminished. Only through freely chosen discipline can life be enjoyed and still kept within the bounds of reason." (Wikipedia)