History of the Peloponnesian War

"I say, therefore, that death hath been in states ordained for a punishment of many offences, and those not so great but far less than this. Yet encouraged by hope, men hazard themselves; nor did any man ever yet enter into a practice which he knew he could not go through with.

And a city when it revolteth, supposeth itself to be better furnished, either of themselves or by their confederates, than it is, or else it would never take the enterprise in hand.

They have it by nature, both men and cities, to commit offences; nor is there any law that can prevent it. For men have gone over all degrees of punishment, augmenting them still, in hope to be less annoyed by malefactors. And it is likely that gentler punishments were inflicted of old even upon the most heinous crimes; but that in tract of time, men continuing to transgress, they were extended afterwards to the taking away of life;

and yet they still transgress. And therefore, either some greater terror than death must be devised, or death will not be enough for coercion. For poverty will always add boldness to necessity; and wealth, covetousness to pride and contempt. And the other [middle] fortunes, they also through human passion, according as they are severally subject to some insuperable one or other, impel men to danger.