Error of opinion may be tolerated where reason is left free to combat it.

A wrong opinion is survivable as long as it can be argued with in the open. Bad ideas that get discussed are examined, tested and mostly worn down; the same ideas driven out of sight harden, gather people, and lose the one thing that could have corrected them. The danger is much less in the error than in the silence around it.

This cuts both ways in your own life. Let people say the thing you think is wrong, and answer it rather than shutting it down. And keep yourself arguable: notice if you have stopped explaining a position and started treating disagreement with it as an offence.