Paradoxes of Rationalists and Cooperation: Prisoner's Dilemma and Newcomb's Problem

Evan Simpson is a philosophy professor and dean of humanities at
McMaster University and the editor of Anti-foundationalism and Practical
Reasoning: Conversations Between Hermeneutics and Analysis.

These essays represent one approach — that of game and decision theory — to questions of morality and rationality, self-interest and cooperation. Suppose that you and your partner have been accused of a crime and are awaiting trial in separate cells. The prosecutor offers you a deal: if neither you nor your partner confesses you are going to spend a year in jail, but if you confess and help convict him you will go free. (He will go to jail for 10 years.) You know that the same deal is being put to the other prisoner and that if you both confess you will both spend several years in jail. Do you accept the offer? Logic suggests that you should, since if you do confess you are better off whether he confesses or not. Unfortunately, the same logic suggests that he should confess as well, in which case you are both worse off than if neither confessed.

There is no agreed-upon solution to this “prisoner’s dilemma” or to the similar problem invented by William Newcomb. The fact has practical importance because the paradoxes can be applied to questions of nuclear disarmament and other relations between states, as well as to real disputes and conflicts of other kinds, with the same disconcerting results. A long introduction for the uninitiated and 19 philosophical papers (eight new, eleven republished) explore solutions in a sophisticated way that will be of interest to economists, psychologists, biologists, political scientists, and mathematicians.