Paul Krugman

#2

Intelligence is a nebulous concept, one that I suspect lacks meaning altogether. Does intelligence refer to brainpower, or to problem solving ability? Is there any difference? Does intelligence perhaps refer to something else, like creativity or intuition? And what do we even mean when we refer to those things? Is intelligence measured by potential or performance? If potential, doesn't this change throughout one's lifetime (if for no other reason than that the physical structure of our brains changes)? If performance, isn't intelligence then nothing more than a statement of historical intellectual triumphs rather than an indicator of future insights? And how do we know that there is even a smartest person alive? Settling on a list of the ten smartest people is probably no less absurd than generating a list of the ten biggest numbers. The concept of intelligence is not clear cut, but this list certainly is.

#4

These are columnists whose editorial opinions I find most interesting, whether or not I always agree.

Requirement: they must publish regularly, ideally once a week or more. This list is only loosely ranked; I find that people writing regular columns tend to be somewhat inconsistent for stretches at a time. Perhaps it is because they become more distracted when working on a book or doing heavy TV appearances or all the other distractions of being a "personal brand".