In an attempt to find out more about how creative people engage in thinking, more than 50 men and women considered to be prominant in the humanities, the arts, and the sciences were interviewed. Letters, diaries and autobiographies of other creative individuals were examined in an effort to provide a broad base for studying the psychology of creativity. Part one explores thought in a developmental way. The chapters in this section deal with the development of thinking among those who were interviewed, including some of the ways these individuals were driven with a need to know and to imagine. Part two focuses on the varied forms of thought, and contains chapters on visual thinking, verbal thinking, scientific thinking, and what Aaron Copeland referred to as the language of emotion, those thoughts realized in music and choreography. The final section explores the differences among human beings in their willingness to pursue and hold the power of ideas, differences that are claimed to partially separate creative thinking from mundane thinking. (TW)