Full Idea
In 'Parmenides' it is argued that a part cannot be part of a many, but must be part of something one.
Gist of Idea
Plato says only a one has parts, and a many does not
Source
report of Plato (Parmenides [c.366 BCE], 157c) by Verity Harte - Plato on Parts and Wholes 3.2
Book Reference
Harte,Verity: 'Plato on Parts and Wholes' [OUP 2002], p.123
A Reaction
This looks like the right way to go with the term 'part'. We presuppose a unity before we even talk of its parts, so we can't get into contradictions and paradoxes about their relationships.
Related Idea
Idea 15850 Anything which has parts must be one thing, and parts are of a one, not of a many [Plato]