Rural life builds the body which luxury destroys

"I realize that in the first ages of the Republic, the Romans always raised their armies in the city itself, but this was at a time when there were no pleasures, no luxuries to enervate them. The Tiber was then their only bath, and in it they refreshed themselves after their exercises and fatigues in the field by swimming. In those days the same man was both soldier and farmer, but a farmer who, when occasion arose, laid aside his tools and put on the sword. The truth of this is confirmed by the instance of Quintius Cincinnatus, who was following the plow when they came to offer him the dictatorship. The chief strength of our armies, then, should be recruited from the country. For it is certain that the less a man is acquainted with the sweets of life, the less reason he has to be afraid of death."

Vegetius. Epitoma rei militaris. [Translated by Lieutenant John Clarke]