An initial argument appeals to the claim that extended simples are conceivable and takes that to be some evidence in favor of their possibility. To conceive of an extended simple, think of an extended—say, cubical—object that has no proper parts. The idea is not, or not merely, that the cube cannot be physically split or cut up. Whether or not it can be split is a separate question. The idea is that there are no proper parts of the cube. Although the object is cubical, it has no top half or bott