This, but as an extension/further thought process for your thesis, whip this on him...
The Roman Empire, created by the DOERS, was an EXCLUSIVE entity in that it's purpose was to conquer and consume. And it pretty much doesn't exist: Rome fell (or declined if you prefer). Some of the physical landmarks of the empire still exist, sure, but the actual Empire is no more...
The collected thoughts of the Greeks, the THINKERS, were ultimately an INCLUSIVE entity, or at least an inviting thing, based on the premise of debate, etc. What that kind of open discourse led to...critical reasoning, logic, advanced math, the sciences, etc. Those are all things that not only endure, but expand and grow more so than any empire ever could.
Peoples who were conquered by the Romans had significant legal rights within the Roman empire (the exact extent of these rights varied over time, but they were explictly INCLUDED in the political process almost from the beginning). To be a citizen of a Greek city-state, you pretty much had to be born there, otherwise you were explicitly EXCLUDED from the political process.