Abstract

This chapter starts with a discussion of Parmenides’ view that there is just one object with no parts. Parmenides’ arguments are rejected. It then moves to Plato’s critique of Parmenides’ view in the _Sophist_. Plato draws a crucial distinction between a true unity and a sum of parts. This raises the question of how to understand mereological wholes, and the matter is examined in the rest of the chapter. It is argued that we may take an object to be identical with the sum of its parts, but not the plurality of its parts. Various objections are considered and rejected. It is also argued that nothingness may be seen as the mereological sum of the empty set. The idea is spelled out in technical detail in a formal appendix to the chapter.