A. The Prisoners’ Dilemma
This common illustration, borrowed from game theory, works as follows: imagine that you and a friend are apprehended by the authorities and charged with a crime. You are each taken to two separate interrogation rooms, from which you cannot communicate with each other, and are presented with two options: you can either keep mum in response to the authorities’ accusation, or you can betray your friend by implicating him as the sole perpetrator of the crime. You and your friend are also advised that one of the following three scenarios will obtain, depending on how each of you responds: (1) If both you and your friend keep mum, you each spend three nights in jail. (2) If one friend keeps mum while the other betrays, the friend who betrays goes scot-free, while the silent-but-betrayed friend spends a month in jail. (3) If both friends betray each other, each of them spends a week in jail. Obviously, each friend’s best bet is to betray the other party, because regardless of the other party’s decision, betraying your friend offers you the best odds of receiving the least amount of punishment. But, of course, if both parties betray each other, they each needlessly wind up worse off than they could otherwise have been. For had they been able to communicate with each other ahead of time, and had they been able to trust each other, they each could have agreed to keep mum, thus ensuring that both parties would have wound up better off than they would have had they each betrayed the other – they each would have spent a mere three nights in jail, rather than a week.
The situation in standard contractarian or social-contract accounts works much the same way: in a lawless society, or in the state of nature, everything is permitted. Thus, if I know that there is nothing stopping my neighbors from lying to me, stealing from me, harming me, or even killing me for the sake of their own personal gain, then I would be foolish if I did not also try to maximize my own self-interest by lying and stealing from all my neighbors. Under such an arrangement, though, everybody winds up worse off than they need be. For while my advantage is promoted by the fact that I can violate my neighbors all I want in order to advance my lot in life, this benefit is more than outweighed by the fact that all my neighbors are themselves each trying to steal from me, lie to me, or harm me . . . anything that might advance their lot in life. The result is that I am much worse off, because anything I might happen to gain by violating my neighbors