That's not what Milton Friedman is saying.

The discussions of the "social responsibili­ties of business" are notable for their analytical looseness and lack of rigor. What does it mean to say that "business" has responsibilities?

So here's the hairy battle of externality: Friedman is saying that business managers have a responsibility to the metrics that are directly quantifiable and directly measurable to the charters of that business. If it's a bank, it needs to make money. If it's a hospital chartered to help as many people as possible, it needs to help as many people as possible. Those are the metrics that are available, those are the goals that should be pursued. By the way, ever seen the word "eleemosynary" before? I haven't. Apparently it means "charitable."

So here's the basic problem: Friedman is saying externalities don't fucking count because they aren't part of the equation. He argued that what does matter is what is in the equation, and if it mattered it would be legislated:

This process raises political questions on two levels: principle and consequences. 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.

In other words, "render unto caesar." Corporations need to make money and the government needs to take care of social needs such that all externalities are appropriately taxed and penalized to force the corporation to make money only in such a way that is socially responsible. But it doesn't take a genius to argue that the government moves hella slower than a predatory corporation. To which Friedman says:

Many a reader who has followed the argu­ment this far may be tempted to remonstrate that it is all well and good to speak of Government's having the responsibility to im­pose taxes and determine expenditures for such "social" purposes as controlling pollu­tion or training the hard-core unemployed, but that the problems are too urgent to wait on the slow course of political processes, that the exercise of social responsibility by busi­nessmen is a quicker and surer way to solve pressing current problems.

Aside from the question of fact–I share Adam Smith's skepticism about the benefits that can be expected from "those who affected to trade for the public good"–this argument must be rejected on grounds of principle. What it amounts to is an assertion that those who favor the taxes and expenditures in question have failed to persuade a majority of their fellow citizens to be of like mind and that they are seeking to attain by undemocratic procedures what they cannot attain by democratic proce­dures. In a free society, it is hard for "evil" people to do "evil," especially since one man's good is another's evil.

TL;DR: TOO FUCKING BAD.

So Friedman's answer to your question is "tax the shit out of greed and pollution so it's no longer so attractive." The fact that you will never get a legislature to move as quickly as a corporate board is, to Milton Friedman, proof that your society doesn't actually want clean air or charity all that much.

Because Milton Friedman was an asshole.

Peculiarly enough, the article practically begs for fascism. But I'll bet the average business pundit never reads that far.