“If all mankind minus one were of one opinion, and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person than he, if he had the power, would be justified in silencing mankind.”John Stuart Mill · Despre libertate · 1859 · capitolul II
The majority has no moral right to silence a minority voice, no matter how solitary it is.
Mill defends free speech in absolute terms: even a single person who thinks differently from everyone else has the right to be heard. Silencing them is as wrong as if they silenced all of humanity. For example, a scientist who challenges an accepted theory, like Galileo, must be allowed to speak, because truth may be on their side.
Why it matters In the age of social media and polarization, this idea reminds us that diversity of opinion is vital for progress.