Thucydides 2.40.

"we Athenians are able to judge at all events if we cannot originate" (Crawley)

This is an important point.  See Simon Goldhill’s chapter, "The City of Words" in his Reading Greek Tragedy, page 63:  Here Goldhill emphasizes the extensive citizen participation [link to Doyle] in managing the polis.  Prospective soldiers voted on declarations of war; every ten  years, a quarter to a third of the citizen body would serve on the Athenian Council that made most executive decisions.  This was an unbureaucratic city without much hierarchy of office, with close citizen involvement in the application of law, no structured political parties, and direct participation.  As Pericles remarks, all Athenians are fit to judge—and each is willing to fight and die.

92:  the mutual interdependence of the citizens is an essential demand of the ideology of city life.  Citizenship puts men in a new relation to each other: "being part of a city requires taking part in a wide range of corporate activities and obligations."