“Free Speech” leans heavily on the philosopher John Stuart Mill’s 1859 classic “On Liberty” to supply the justification for freedom of argumentation and expression. Mill’s arguments boil down to three propositions. First, truth matters. Second, the best way to get at truth is to allow a serious and open contest of ideas. Mill likened this to a marketplace, although it seems closer to a college seminar. Third, the government is only really justified in regulating us if do we violence to others - or intentionally stir others to violence.
Mill thought free speech precious because it would maximize the happiness of society. Many who came after Mill have pointed out that his utilitarian calculus doesn’t really add up. Freewheeling speech may lead people to the truth, or it may move them in the other direction. Ultimately, freedom of speech - with its implied and unpopular right to cause offense - matters because freedom matters.
Jeremy Lott is author of “The Warm Bucket Brigade: The Story of the American Vice Presidency” and editor of Labor Watch.