Also, your paragraph:

> In this instance, that logic appears fairly innocuous, but what makes me nervous is that this same logic is what leads to the Sean Hannity’s of the world, the Breitbarts, the InfoWars. If the same logical progression can lead someone to find truth in such disparate and, from my perspective, repugnant sources, then isn’t the logic itself flawed?

Expanding on my comments below, the way I would explain this is as a feedback loop. Imagine two people who start out with the same knowledge but one is a little better than the other at reasoning and examining data. Over time, the accuracy of their “knowledge base” will diverge more and more, because if your “knowledge base” is bad, then you will be less able to evaluate new sources of information. The “dumb” person will start to trust progressively worse sources of information because they reaffirm what they already “know”, thereby corrupting their knowledge base further, and so on. Conversely, the “smart” person will ideally get closer to the truth over time.

I am afraid there is no easy answer, except to periodically re-examine your fundamental assumptions against hard data. And even then, it is always fallible.

For me, it helps to think of all knowledge as probabilistic. There is nothing with certain truth, only sense data and probabilities attached to different propositions. Learning, then, is just updating the probabilities. In my worldview there is a certain but very small probability that every word Breitbart says is true.