John Maynard Keynes is widely recognized as one of the greatest economists of the 20 th century. For a growing number of his interpreters, Keynes’s emphasis on uncertainty and on the psychological aspects of expectations about the future are among his most significant contributions. References to Keynes’s notions of confidence and animal spirits, for example, have increasingly appeared in the economic literature. In sociology, a stimulating recent book by Jack Barbalet (1998) tries to improve our understanding of social structure by redefining the role of emotions in social life. Barbalet also wants to correct what he understands as an insufficient attention to time on the part of social theorists. This double objective leads him to deal with confidence and some of Keynes’s ideas. His book represents a most valuable contribution to the sociology of emotions, time and uncertainty. The purpose of this paper is to comment on Barbalet’s discussion of confidence and the theory of action, and to contrast it with an alternative approach. Both Barbalet’s position and the alternative presented here involve an interpretation of Keynes’s theory of economic behavior under uncertainty, but go beyond doctrinal-historical issues and formulate original theoretical propositions. The present paper is intended as a positive contribution to the interaction between economists and sociologists interested in these issues. Barbalet’s book already represents an important step in this direction, for his social analysis considers, and incorporates insights from, the work of several economists, in addition to conveying well-founded criticisms of standard economic theory. As far as Barbalet’s interpretation of Keynes is concerned, the paper points out Keynes’s ambiguity regarding important issues and identifies interesting points of Keynes’s theory that Barbalet does not discuss or emphasize. The paper produces evidence against Barbalet’s equation of confidence and animal spirits in Keynes. It also shows that Keynes distinguished between expectations and confidence, a distinction not explicitly made by Barbalet. In addition, the paper enriches Barbalet’s discussion of Keynes’s monetary theory by relating uncertainty to the precautionary motive for liquidity preference. Moving from the history of thought to theory, the paper proposes an alternative analysis of confidence and action, and contrasts it with Barbalet’s approach. This alternative approach distinguishes between confidence and expectations, and suggests that these two elements are ultimately determined by three factors: knowledge, animal spirits (redefined as an optimistic disposition to face uncertainty) and creativity. The first two factors are seen as determinants of confidence through their influence on what is called uncertainty perception and willingness to face uncertainty (or uncertainty aversion). The paper is organized as follows. It begins by summarizing some aspects of Barbalet’s views on confidence, in section 1. It proceeds, in section 2, by presenting Barbalet’s interpretation of Keynes and discussing it. The next step is to present, in section 3, another theory of action in which confidence plays a crucial role. This alternative approach, which uses Keynes’s insights but goes beyond his work, is then contrasted with Barbalet’s views.