… is from chapter 4 of William Graham Sumner’s 1885 book, Protectionism: the -ism Which Teaches that Waste Makes Wealth:
So the nation which has free trade when the others do not have it, gains the most by comparison with them. It gains while they impoverish themselves. If all had free trade all would be better off, but then no one would profit from it more than others. If this were not true, if the man who first sees the truth and first acts wisely did not get a special premium for it, the whole moral order of the universe would have to be altered, for no reform or improvement could be tried until unanimous consent was obtained. If a man or a nation does right, the rewards of doing right are obtained. They are not as great as could be obtained if all did right, but they are greater than those enjoy who still do wrong.