I frequently engage in conversations about beliefs. It’s kinda my thing. People often ask about the history of my beliefs or of someone else’s beliefs, especially religious beliefs. Everyone likes to construct a coherent story that will help them make sense of another person’s views. “That’s how they were raised,” or “they’re just reacting against such-and-such,” or “they went though some trauma that caused them to change their beliefs.” While I do find all this psychologically interesting, when it comes to evaluating a person’s beliefs, it is irrelevant.
In the video, I don’t explain why the past is irrelevant. The past doesn’t matter because of the nature of epistemic justification. Put simply, the quality of your beliefs depends on how well your reasons support them. And the only reasons that count now are the reasons you have now. You may have had different reasons in the past, and maybe you’ll change your reasons in the future, but none of that matters now.
An Analogy of Support
Imagine a bridge being supported by stone columns. The integrity and strength of that bridge depends on the quality of the support now. The columns may be crumbling now, even if they were strong in the past. Conversely, a bridge that was decrepit last year but has been completely rebuilt is strong now, even though it was weak in the recent past. When you drive over the bridge, all you care about is the condition of the supports now. So it is with beliefs and their supports. And we can evaluate this objectively with standards of logic.