freiberg which means free city, which is perfect. he wasn't a conservative. he was a liberal, a libertarian. >> in your most recent book, "bourgeois equality," you talk about him as young hayek, middle-aged hayek and older hayek. >> well, he was -- >> did he change his opinions? >> not too much. here's what happened. he was an economists economist or give one the leading economist in the world in the making 30s and 40s. he was commonly thought by edwin as john maynard keynes equal. and, but later in the '50s and 60s and 70s, he turned to philosophy, to political philosophy. so i think that's a big change. it's not that he changed his opinions about what we unfortunately call capitalism. he thought it was a good thing. he thought that socialism is hard to impossible to make work. >> host: in your book, professor, you write that there is a great difference between classic liberalism and contemporary libertarian. give us a definition of both of those. >> guest: i'm not sure where that came from in the book because i'm not sure i believe it. but i believe that th