History of the Peloponnesian War

For these reasons they should not hesitate to exchange peace for war. If wise men remain quiet, while they are not injured, brave men abandon peace for war when they are injured, returning to an understanding on a favorable opportunity: in fact, they are neither intoxicated by their success in war, nor disposed to take an injury for the sake of the delightful tranquillity of peace.

Indeed, to falter for the sake of such delights is, if you remain inactive, the quickest way of losing the sweets of repose to which you cling; while to conceive extravagant pretensions from success in war is to forget how hollow is the confidence by which you are elated.

For if many ill-conceived plans have succeeded through the still greater fatuity of an opponent, many more, apparently well laid, have on the contrary ended in disgrace. The confidence with which we form our schemes is never completely justified in their execution; speculation is carried on in safety, but, when it comes to action, fear causes failure.