Every year or so, I re-read John Stuart Mill’s great statement of liberal principles and values, On Liberty (first published in 1859). More than any other, I suspect, this book has shaped my own thinking about politics, law, and society. Each time I read it, I notice new twists and subtleties. It’s always worth returning to such classic texts to examine their original arguments: these often lose much of their richness and persuasive power in more modern summaries.
On Liberty provides a masterful defense of individual freedom and, in particular, a certain conception of free speech. Mill does not defend a mere freedom from government censorship and control. He is equally, or perhaps more, worried about informal social constraints on our ability to think, speak, and live as we please, subject only to the implications of the harm principle, which he borrowed from Wilhelm von Humboldt. To simplify drastically, this principle involves an imperative not to inflict direct harm on others.
As Mill acknowledges, governments possess great power. They can imprison us, or worse, if we violate their commands. But Mill also identifies what he calls “the tyranny of the prevailing opinion and feeling,” the intrusive and ubiquitous pressures to conform that come from society at large and particularly from the expectations of people with whom we interact.