David Horacek

There is no possible world in which someone travels back in time and kills herself as a baby. All possible worlds are internally consistent; the one just described would not be. For this reason, autoinfanticide is metaphysically impossible. This metaphysical impossibility is philosophically intriguing because unlike most impossible events, we can vividly picture how it might look. Time travel itself seems possible, and for those who arrive in the past with proper equipment and training, the actual infanticide should not be difficult. The considerations in this paper have led me to conclude that there are indeterministic worlds in which instances of autoinfanticide have a chance of succeeding, sometimes even a high chance. Some may be tempted to resist this conclusion, uncomfortable with the notion that something metaphysically impossible can have a positive chance. Understandably, they expect something which happens at no world to also have no chance of happening. However, no plausible theory of chance fits these preconceptions.