In which field did the Athenians make the most lasting contributions to western civilization?

In ancient Greece, only slaves went to school, where they were taught to be better slaves. This system was later adopted by the Brahmans in India to educate lower classes, while their own children were tutored at home. The system went to Prussia to train soldiers and it was there that the only change was made. Instead of conducting classes while walking outside, the Prussians conducted them while seated inside. The USA and then Great Britain adopted the system for public schools.

There are two kinds of education. Lower classes have always been educated to perform a job. That system produces servants, technicians, and soldiers. Upper classes have always had a very different education in a system that produces generals, philosophers, and entrepreneurs. Here are a book and an essay to help you understand:
The Lost Tools of Learning www.gbt.org/text/sayers.html
The Underground History Of Public Education (PDF) mhkeehn.tripod.com/ughoae.pdf