Imagine that Sally (S) robs a bank (call this event R) in 1975 (t1) and is caught. However, due to various complications with the prosecution, she is not put on trial until 2011 (t2). During this time, via natural processes the atoms that compose her body have been completely replaced with other ones. Now for the argument.
1. S is morally accountable for R’s occurrence at t1, even at t2.
2. Substances are the only things that can cause events.
3. Only the thing that caused an event can be morally accountable for that event.
4. If materialism is true then S at t1 is not an identical substance to S at t2.
5. From (2), (3) and (4), if materialism is true then Sally is not morally accountable for R at t2.
6. From (1) and (5), materialism is false.