History of the Peloponnesian War

For they are not attacking our nations, because they are different, and from their hatred of one of them; but from coveting the good things of Sicily, which we possess in common. And this they have now shown upon the invitation of the Chalcidian race:

for to those who had never yet assisted them on the ground of their alliance, they themselves with forwardness answered their claim, beyond the letter of the compact. And very excusable is it that the Athenians should practise this covetousness and forecasting;