Every year I teach epistemology, which is Greek for “theory of knowledge.” My students and I try to understand what knowledge is, and how to get it. Knowledge starts with evidence. We might acquire evidence from scientific experiments, combing through books, talking to others, or even just opening our eyes and seeing the world around us.
But evidence doesn’t always wear its lessons on its sleeve. Sometimes we have to combine multiple pieces of evidence, or dig deeper into what our evidence says, to draw a conclusion. This requires reasoning.
Most of my research is about reasoning. In particular I study Bayesian models of reasoning, which are based on statistics and probability mathematics.
I ask what makes reasoning good, or bad. Is there only one good way to reason? If two people start from the same evidence, and reach different conclusions, must one of them have made a mistake? Or do our different perspectives, upbringings and points of view allow us to draw different lessons from the same experiences?
Two people might watch the same political debate and disagree about which candidate would be best for our country. Two scientists might look at the same experimental data, and form different theories. Most importantly, I ask what we should do when we find ourselves in these disagreements.
Must we dismiss the other person’s conclusions as confused or ill-informed? Or can we learn from different perspectives, without having to abandon our own?
Despite being studied for millennia, these questions feel more important now than ever.
This essay originally appeared in the Wisconsin State Journal’s Fueling Discovery section on May 4, 2020. Fueling Discovery is a special partnership between the Wisconsin State Journal and the College of Letters & Science.