This is the first draft of a chapter in a planned book on the Prisoner's Dilemma, edited by Martin Peterson, to be published by Cambridge University Press. It discusses the nature of the conditionals involved in deliberation, taking the Prisoner's Dilemma game as point of departure.

This is the first draft of a chapter in a planned book on the Prisoner’s Dilemma, edited by Martin Peterson, to be published by Cambridge University Press. It discusses the nature of the conditionals involved in deliberation, taking the Prisoner's Dilemma game as point of departure.

In a seminal paper, Aumann (1987, Econometrica 55, 1–18) showed how the choices of rational players could be analyzed in a unified state space framework. His innovation was to include the choices of the players in the description of the states, thus abolishing Savage’s (1954, The...