The Wealth of Nations by Part 5 Chapter 1 Page 17

entrusted with the execution of those ordinances, or from some other cause, they appear to have been universally neglected; and in the progress of all those governments, military exercises seem to have gone gradually into disuse among the great body of the people.

In the republics of ancient Greece and Rome, during the whole period of their existence, and under the feudal governments for a considerable time after their first establishment, the trade of a soldier was not a separate, distinct trade, which constituted the sole or principal occupation of a particular class of citizens. Every subject of the state, whatever might be the ordinary trade or occupation by which he gained his livelihood, considered himself, upon all ordinary occasions, as fit likewise to exercise the trade of a soldier, and upon many extraordinary occasions as bound to exercise it.