"The Social Responsibility of Business is to Increase its Profits" in The New York Times Magazine (13 September 1970) http://www.colorado.edu/studentgroups/libertarians/issues/friedman-soc-resp-business.html
Context: On the level of political principle, the imposition of taxes and the expenditure of tax proceeds are governmental functions. We have established elaborate constitutional, parliamentary and judicial provisions to control these functions, to assure that taxes are imposed so far as possible in accordance with the preferences and desires of the public — after all, "taxation without representation" was one of the battle cries of the American Revolution. We have a system of checks and balances to separate the legislative function of imposing taxes and enacting expenditures from the executive function of collecting taxes and administering expenditure programs and from the judicial function of mediating disputes and interpreting the law.
Here the businessman — self-selected or appointed directly or indirectly by stockholders — is to be simultaneously legislator, executive and, jurist. He is to decide whom to tax by how much and for what purpose, and he is to spend the proceeds — all this guided only by general exhortations from on high to restrain inflation, improve the environment, fight poverty and so on and on.