The irony of this “thinkers” list is that it does not bear thinking about too closely. The problems of definition and judgment that it involves would discourage more rigorous souls. But some criteria must be spelled out. What is a public intellectual? Someone who has shown distinction in their own field along with the ability to communicate ideas and influence debate outside of it. Candidates must have been alive, and still active in public life (though many on this list are past their prime). Such criteria ruled out the likes of Aleksandr Solzhenitsyn and Milton Friedman, who would have been automatic inclusions 20 or so years ago. This list is about public influence, not intrinsic achievement. And that is where things get really tricky. Judging influence is hard enough inside one’s own culture, but when you are peering across cultures and languages, the problem becomes far harder. Obviously our list of 100 has been influenced by where most of us sit, in the English-speaking West. We tried to avoid the “box ticking” problem of having x Chinese, y economists and z under-50s. But we have also tried to give due weight to the important thinkers in all the main intellectual disciplines and centers of population. We also tried to ensure that all names on the list are influential in at least a few countries in their region, if not the entire globe. Voting closed October 10, 2005. More than 20,000 people voted in this poll. See results below.