… is from page 51 of Milton and Rose Friedman’s 1980 classic, Free To Choose :
In a free trade world, as in a free economy in any one country, transactions take place among private entities – individuals, business enterprises, charitable organizations. The terms at which any transaction takes place are agreed on by all the parties to that transaction. The transaction will not take place unless all parties believe they will benefit from it. As a result, the interests of the various parties are harmonized. Cooperation, not conflict, is the rule.