Every Englishman must be allowed to buy in the cheapest market, and sell in the dearest.
Sir Robert Peel, quoted by Frédéric Bastiat
Complete Works, Volume 1, pages 334 to 386 (in French)
This quote dating back to the Speech on Tariffs by Sir Robert Peel, then Prime Minister of Great-Britain, on May 10th 1842 appears twice, at pages 349 and 358 of the comparative analysis on tariffs from which it is extracted. It sums up clearly one of the objectives of free-trade. However and despite what its opponents think when they see in it only a “crude materialistic interest”, it constitutes a necessary step of free-trade but not its essence. This is the reason why Frédéric Bastiat analyses the question of tariffs over fifty pages rather than a single phrase!
Indeed, he also regrets that Sir Robert Peel, who was supported by the Tories, implements these policies partially only while the Whigs were more consistent concerning free-trade. However, Robert Peel is also the man who will repel the Corn Laws two years later and this is an honour that will accompany him to the grave.
An interesting point in this approach of tariffs reduction is that it gave the opportunity to observe the Laffer effect, which will be formalised by Arthur Laffer more than hundred years later. This curve conveying the fact that the base of a tax is as important as its rate in order to optimise its collection has a lot of detractors. It seems clear though that, at least when applied to tariffs, it is as valid as the curve of supply and demand (even if the optimal rate is never predefined and commands the same difficulties for a measured forecast as most other economic phenomena).