These past few months, I've become more interested in how I know, than what I know. While facts play a big role in the formation of my values and beliefs, the primary concern is summed up in my title: 'How do I know?'
How did I decide that my favorite set of values are 'right,' opposed to all those 'wrong' values? How did I settle on my particular list of 'good to know' facts, and how do I test and retest their reliability in the real world?
Epistemology is the term philosophers use for this question, How do I know what I think I know? Our parents, teachers, and other important early voices give us our childhood epistemology. Children are at the epistemological mercy of the adults surrounding them.
Without the cognitive tools of experience, common sense, or mature logical reasoning, children must answer the question How do you know? with 'so and so told me.' Which is another way to say 'I don't know, but I trust my mom (or teacher, or doctor, or pastor, or grandpa), and they said so'.
Of course, as children develop into adults, hearsay and appeals to authority are increasingly unacceptable, as those tools mentioned earlier reveal themselves to be more reliable. Life experience, common sense, and especially scientific evidence-based reasoning are widely-trusted and universally accepted epistemological tools in almost every realm where accuracy matters.
Almost. One form of hearsay remains despite the best attempts of enlightened reasoning to relegate it to the dustbin of history: faith.
I have recently finished a long period in my life during which I trusted faith as much or more than other ways of knowing things. (I'm not interested in the many different definitions Christians toss about for faith; whatever you count as the 'biblical' or official meaning of it, the way it is experienced by believers is the important thing to me.)
For me, it was the easiest way to dismiss doubts which arose as my years of studying the Bible grew into decades. Whatever could not easily be explained the way most difficult questions are-- logical reasoning, evidence-gathering, observation, consulting experts and their research, etc-- was explained away, by saying to myself, "Well, I guess I'll just have to take that on faith, and ask God about it in heaven."
I learned that practice of explaining difficult things away by faith early on in my Christian experience, and encountered it consistently throughout the full period during which I interacted with many fellow students of the Bible.
I have abandoned faith now, and no longer explain things away with capricious appeals to a future Q&A session with an imaginary Sky God. It's tougher to think things all the way through, but ultimately more satisfying because of the higher confidence level I can have in those values and beliefs which survive that testing process.
It's much tougher to deal with the many regrets I have that I ever swallowed the poison pill of faith, wrapped as it was in a pleasant coating of fellowship and social interaction. But life goes on, and I strive to make the best of it, using far superior tools than the one I left in the dustbin of my own history: faith.