 A third argument from STR to perdurantism does not rely on the claim that STR is out-and-out incompatible with endurantism. Instead, the claim is that STR highlights a phenomenon which can better be explained by perdurantists than by endurantists. To understand the phenomenon, imagine a three-dimensional cylindrical chocolate cake which you want to cut up into two-dimensional pieces (you’ve got a lot of friends). If you cut only at right angles to the length of the cake, then each piece will be circular. But if you cut at a different angle, then each piece will be oval. The cylindrical shape of the cake explains the shapes of the various pieces produced by cutting at various angles.