244 An Introduction to Immortalist Morality In a recent Nature paper [2], a moral dilemma was described. Two subjects were asked to share a pot of money, say $100, in which one person decided the amount that each of them got and the other person either had to accept it or neither of them would get any money at all. They only play once. If A decides that he should get $95, and offers B only $5, it might seem logical for B to accept. After all, B gets $5 if he accepts, and nothing if he does not. But when the game is played in real life, people refuse to accept splits that are too unequal, forego- ing personal gain in order to punish the other guy. Moral  behavior  is  only  of  advantage  when  the  game  is played many times (an ‘iterated game’). Over many games it is logical for the person who is offered an unfair split to decline, and for the person splitting the money to do so fairly. This is because it is known that the optimum strategy for inter- actions between two parties over the long run is simple ‘Tit for Tat’. The success of the ‘Tit for Tat’ strategy was discovered in a worldwide computer competition in 1981. The competi- tion was looking for a solution to a moral dilemma known as ‘The Prisoner’s Dilemma.’ There is a lesson there. In the real world kindness to strang- ers is only really to one’s advantage over the long run. In fact, morality would only be perfectly logical if we lived forever. People have to stick around long enough to reap all of the consequences of their actions. When humans act morally they are in a sense acting as if they are immortal! We can conjec- ture that human morality is in part explained by the uniquely human sense of time. Only sentient beings capable of ratio- nal thought can plan far into the future, and only they can understand that the world will continue to carry on without them should they die. Humans are motivated to act morally because, in their imaginations, they can consider what people would think of them if they were alive at any time into the future – be it 5 minutes from now or 5 centuries.