… is from a September 4th, 1832 speech by Thomas Babington Macaulay in Parliament, as quoted on page 224 of John Clive’s magnificent 1973 biography of Macaulay, Macaulay: The Shaping of the Historian:
As I am for freedom of discussion and worship, so I am also for freedom of trade. I am for a system under which we may sell where can sell dearest, and buy where we can buy cheapest.
