One of the best gifts my father gave me as I was growing up was challenging my thinking about pretty much every topic. He made me explain my reasons and defend my ideas all the time. Sometimes it was frustrating, and I didn’t win all of the arguments, but I learned how to ask hard questions and evaluate my own ideas. A recurring piece of advice he gave me along the way was “never believe your own propaganda.” The idea was simple: every side presents their own position as stronger, better, mightier, and more righteous than it actually is. They also present their opponents as dumber, weaker, mor...