The search for the physiological (often neurophysiological) basis for complex human behavior has been carried to a new pitch in recent years, largely as a result of new measurement and observation techniques. There is little doubt that this line of investigation has a great future, even though some current exercises may be premature, crude, or speculative. I shall mention three sets of findings that seem particularly relevant to the purposes of this book.

Fear

In Chapter 8 I asserted that emotions typically are triggered by beliefs, or cognitive antecedents. I get angry if I believe that your bumping into me was intentional, reckless, or negligent, but not if I believe it was an accident caused by a third party's bumping into you or by a sudden movement of the train. In Proust's La prisonnière, the feelings of jealousy in the Narrator wax and wane with his beliefs about what Albertine may have been up to during the periods he let her out of his sight. One might ask, however, whether emotions are not sometimes caused by mere perceptions that, unlike beliefs, are not “about” anything. Descartes thought, for instance, that surprise or astonishment “can happen before we know in the least whether this object is suitable to us or not.”