History of the Peloponnesian War

For in that we shall be at our own liberty, though all the Sicilians together were against it. Let not the speech of Nicias, tending only to laziness and to the stirring of debate between the young men and the old, avert you from it; but with the same decency wherewith your ancestors, consulting young and old together, have brought our dominion to the present height, endeavour you likewise to enlarge the same. And think not that youth or age, one without the other, is of any effect, but that the simplest, the middle sort, and the exactest judgments tempered together is it that doth the greatest good; and that a state as well as any other thing will, if it rest, wear out of itself, and all men's knowledge decay; whereas by the exercise of war experience will continually increase, and the city will get a habit of resisting the enemy, not with words, but action.

In sum, this is my opinion: that a state accustomed to be active, if it once grow idle, will quickly be subjected by the change; and that they of all men are most surely planted that with most unity observe the present laws and customs, though not always of the best.