… is from page 79 of David Rose’s excellent 2011 book, The Moral Foundation of Economic Behavior  (original emphasis):
The problem that societies must solve, if they are to enjoy the benefits of efficiently organizing economic activity in large groups, is not getting people to care more about each other, or getting them to do nice things for one another. The problem that societies must solve is combatting their willingness to take advantage of each other, to behave opportunistically.
David’s argument is that, while secure property rights, well-developed and predictable contract law, and other institutions are necessary to combat prosperity-destroying opportunism, they are not sufficient. In addition there is needed the proper moral foundation.