I first got interested in personality psychology long ago as a double-degree student of psychology and philosophy. I was intrigued by the psychology of philosophical divisions and started thinking about how people’s views of the world reflect their personalities. It seemed to me that there was frequently a coherence between the personalities of philosophers and the philosophical positions they adopted. Historical examples There are many historical examples consistent with this position. An example that comes to mind is Arthur Schopenhauer—a 19th century thinker known as the philosopher of pessimism, who was also known to be cynical and disagreeable in his personal life. Another obvious example is Immanuel Kant—an 18th century…