When the art of war, too, has gradually grown up to be a very intricate and complicated science; when the event of war ceases to be determined, as in the first ages of society, by a single irregular skirmish or battle; but when the contest is generally spun out through several different campaigns, each of which lasts during the greater part of the year; it becomes universally necessary that the public should maintain those who serve the public in war, at least while they are employed in that service.