The Metaphysical Club by Louis Menand

“The constitutional law of free speech is the most important benefit to come out of the way of thinking that emerged in Cambridge and elsewhere in the decades after the Civil War. It makes the value of an idea not its correspondence to a preexisting reality or a metaphysical truth, but simply the difference it makes int he life of the group. Holmes’s conceit of a ‘marketplace of ideas’ suffers from the defect of all market theories: exogenous elements are always in play to keep marketplaces from being truly competitive. Some ideas just never make it to the public. But it is the metaphor of probabilistic thinking: the more arrows you shoot at the target, the better sense you will have of the bull’s eye. The more individual variations, the greater the chances that the group will survive. We do not (on Holmes’s reasoning) permit the free expression of ideas because some individual may have the right one. No individual alone can have the right one. We permit free expression because we need the resources of the whole group to get us the ideas we need. Thinking is a social activity. I tolerate your thought because it is part of my thought—even when my thought defines itself in opposition to yours.”

-Louis Menand, 2001