A "Progressive's" Anti-Progressive Argument Against Liberty

Michael Lind of Salon.com thinks he has us stumped. " If your approach is so great, why hasn’t any country anywhere in the world ever tried it?"

I really liked Tom Wood's response, as well as Bob Murphy's brief note. Here's what I have to add: this  attack is supposedly from a "progressive" author and website. The irony is palpable, then, to see them use such an anti-progressive line of argumentation: If x hasn't been tried, it must not be that great.