— Thucydides Greek historian and Athenian general 460
Variant translation: "Instead, we think the plans of our neighbors are as good as our own, and we can't work out whose chances at war are better in a speech. So we always make our preparations in action, on the assumption that our enemies know what they are doing. We should not build our hopes on the belief that they will make mistakes, but on our own careful foresight. And we should not think there is much difference between one man and another, except that the winner will be the one whose education was the most severe." Translation by Paul Woodruff.
Variant translation: "There is no need to suppose that human beings differ very much from one another: but it is true that the ones who come out on top are the ones who have been trained in the hardest school." Note: Some versions omit the "who have been".
Book I, 1.84-