To Archidamus (76)

an army which, in its freedom from ordinary cares and in having no other duty but that of war, would resemble a mercenary force, but in point of native valor and of disciplined habits would be like no army that could be levied in all the world—an army, moreover, which would have no fixed government, but would be able to bivouac in the open fields and to range the country at will, readily making itself neighbor to any people at its pleasure, and regarding every place which offered advantages for waging war as its fatherland?