Full Idea
Plato was less concerned than Aristotle with the project of how to account, in completely general terms, for the source of unity within a mereologically complex object.
Gist of Idea
Plato was less concerned than Aristotle with the source of unity in a complex object
Source
report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.5
Book Reference
Koslicki,Kathrin: 'The Structure of Objects' [OUP 2008], p.120
A Reaction
Plato seems to have simply asserted that some sort of harmony held things together. Aristotles puts the forms [eidos] within objects, rather than external, so he has to give a fuller account of what is going on in an object. He never managed it!