regularly questions himself or herself. Only an epistemologically closed poseur thinks that they already know everything.
They say, “A political philosophy, a political philosophy, I already have a political philosophy and there can be no more political philosophy! I am just right!”
In other words, they are epistemically closed. They cannot learn anything new because by definition that would mean that they were not 100% right before. And that is very threatening to their ego and to their very sense of self! So they simply go about actually knowing very little, but are cocksure about everything.