The Wealth of Nations by Part 5 Chapter 1 Page 30

In respect for their officers, in the habit of ready obedience, they approach nearest to standing armies. The highland militia, when it served under its own chieftains, had some advantage of the same kind. As the highlanders, however, were not wandering, but stationary shepherds, as they had all a fixed habitation, and were not, in peaceable times, accustomed to follow their chieftain from place to place, so in time of war they were less willing to follow him to any considerable distance, or to continue for any long time in the field.

When they had acquired any booty they were eager to return home, and his authority was seldom sufficient to detain them. In point of obedience they were always much inferior to what is reported of the Tartars and Arabs. As the highlanders too, from their stationary life, spend less of their