"We can never be sure that the opinion we are endeavouring to stifle is a false opinion; and even if we were sure, stifling it would be an evil still"

This quote by John Stuart Mill is a suggestion that we ought to beware when trying to suppress an opinion. We can never be specific that the viewpoint we are trying to suppress is incorrect, and even if we made certain, it would still be incorrect to try and suppress it. Mill is suggesting that we need to be open to various viewpoints, even if we disagree with them, which we need to not try to silence those who hold them. He is advocating for flexibility of idea and expression, and for the right to reveal our viewpoints without fear of retribution. This quote serves as a tip that we should be tolerant of different viewpoints, and that we need to not attempt to suppress them.