Occasionally, I try to explain why it is that I didn't go through with seminary. The reasons are legion, but the kicker was that I didn't any longer have the sort of faith that would be required for one to climb into a pulpit. When I say this I usually get a look that says that I'm weird or I'm just being self-deprecating. I am weird and, when I'm not being pedantic, I tend to put myself down. That's not all that's going on in this case.
What I mean is that I lacked the certainty required for a job teaching that faith or any other. This is in spite of my real affection for the faith in which I was raised.
It might be that I am just, as Nietzsche said, making a necessity out of virtue as all ascetics do; but, certainty seems to me to be almost always an intellectual vice. And, to be clear, it is as rampant in those who claim no faith, as in those who do.
I suppose certainty—like the vices of passion—might be well-suited for practical concerns, but the certain mind is a closed mind. Having certainty there is no more need for questioning. And, no more need for discussion. (And, as Mill might have said, no more need to remind ourselves why we believe as we do, in the first place. For this reason, though there are some moral precepts that I am almost certain of, even these need constant defense and justification.) Only proselytizing and judging those who differ are called for.
This might be why an avowal of certainty kills my interest in conversation. Maybe, I'm actually being virtuous.
Or maybe I'm just unable to see the certain truths.