… is from page 123 of the 1992 collection of some of William Graham Sumner’s finest essays, On Liberty, Society, and Politics (Roger C. Bannister, ed.); specifically, this quotation is from Sumner’s January 1881 Princeton Review essay, “The Argument against Protective Taxes”:
What, then, I ask, is the rest of the world to do for us? If we take all the industries, how will they pay us for what we do for them? Competition is the force which under freedom indicates to us what we can do for ourselves and them, and what we can let them do for us to our final maximum advantage. To shut off competition and go into the industries which the ignorant empiricism of Congress or the caprice of individuals may select, is like unhinging the compass and steering the ship by chance.