For in other matters when calamity comes on one, then damage is sustained; but in the case of revenues, not only the arrival of evil, but the bare dread of it, brings disaster. For when the troops of the enemy are not far off, even though no actual irruption takes place, still the flocks are abandoned, agriculture is relinquished, the sailing of merchants is at an end. And accordingly, neither from harbour dues, nor from tenths, nor from the tax on pasture lands, can any revenue be maintained. And therefore it often happens that the produce of an entire year is lost by one rumour of danger, and by one alarm of war.