This essay on Nozick and libertarianism is taking a lot of heat on the blogosphere.
I understand why the bloggers (mostly libertarians) don't like it. For starters, Metcalf is probably wrong about something claims in the essay--a lot of is about the psychology of what is going on in libertarian's heads. Second, everyone get emotional when insulted.
But I still think it's a good essay with a substantive claim: libertarians confuse capital with human capital, or in other words, spend so much time trying to arrange institutions to ensure that uniquely talented people get money, they forget that most people with money are rich because they have crap (capital) not human capital. He also has a decent explanation of the main problem with libertarianism: the perfect competition model is often a bad approximation--though he leaves out a the second half of the point, that we can distinguish when it does and doesn't fit pretty well.
Is that claim of interest or worth discussing? Yes! The libertarians on the blogosphere don't need to be psychoanalyzed, but the average idiot on Facebook who insists that cigarette labels are an affront to human dignity despite making smokers and non-smokers happier does need to be psychoanalyzed. There is a large class of people smart enough to understand perfect markets in outline but not smart enough to understand asymmetric information, behavioral economics, public goods and why market fails in general. We need to understand how to treat (medically) those people.