An obstinate man does not hold opinions, but they hold him.

There is a point where a view stops being something you have and becomes something you are. After that, questioning it feels like an attack on you rather than an examination of the idea, and you will defend it past the point where you privately believe it. The giveaway is the heat: the strength of your reaction has stopped matching the importance of the question. What you cannot put down is not a conviction, it is a possession that owns you.

Pick one position you hold strongly and try to state the best case against it, in good faith, for five minutes.