History of the Peloponnesian War

Thus every kind of villany arose in Greece from these seditions. Simplicity which is a very large ingredient in a noble nature, was laughed down and disappeared; and mutual opposition of feeling, with a want of confidence, prevailed to a great extent.

For there was neither promise that could be depended on, nor oath that struck them with fear, t put an end to their strife; but all being in their calculations more strongly inclined to despair of any thing proving trustworthy, they looked forward to their own escape from suffering more easily than they could place confidence [in arrangements with others].

And the men of more homely wit, generally speaking, had the advantage; for through fearing their own deficiency and the cleverness of their opponents, lest thy might be worsted in words, and be first plotted against by means of the versatility of their enemy's genius, they proceeded boldly to deeds.

Whereas their opponents, arrogantly thinking that they should be aware beforehand, and that there was no need for their securing by action what they could by stratagem, were unguarded and more often ruined.