Richard Ebeling has posted Lecture #3 which discusses the market as a process of competitive cooperation. Richard focuses on the division of labor and the extent of the market.
Again, great stuff to think seriously about with your students.
The critical question for political economy is to discover that institutional pattern that enables individuals and groups to realize the gains from productive specialization and live in peaceful cooperation. From the Scottish Moral Philosophers to the Contemporary Austrian School of Economics, the answer was to be found in private property and freedom of contract protected by the rule of law.