Many advocates of free speech are unaware of its fundamental importance. They argue that freedom of speech is essential to civilized society because speech is the means by which people convey ideas. This is true. But the value of speech is much deeper than that.
Speaking is not only essential to the transmission of ideas; it is also essential to the formation and validation of ideas. Speaking is essential to thinking.
Of course, we can think to a substantial extent without speaking. But much of the complex and abstract thinking on which human flourishing depends can proceed only in conjunction with communication, critical discourse, and debate. This is why scientists such as Galileo, Newton, and Darwin regularly presented their ideas in venues where other scientists would examine and challenge them. Galileo, for instance, presented his ideas at Accademia dei Lincei, a forum in Rome established specifically for scientists to discuss and debate their hypotheses and theories. (That the Church later silenced Galileo for promoting the heliocentric theory highlights the importance of the subject at hand.) Newton presented his ideas at the Royal Society, an association in London dedicated to advancing science through discussion and debate. Darwin presented his ideas at the Plinian Society, a fraternity at the University of Edinburgh dedicated to the discussion of nature, science, and unorthodox views. These world-changing men understood the value of critical analysis and argumentation in developing their ideas and sharpening their minds. . . .