“The wish is parent to the thought, and that is why nothing is easier than self-deceit. For what each person wishes, that they also believe to be true.”  Demosthenes

So Dr. Robert Zimmer, president of the University of Chicago, starts his speech “Liberal Arts, Free Expression, and the Demosthenes-Feynman Trap.” Feynman, in character, said it more simply in 1974:

“The first principle is that you must not fool yourself–and you are the easiest person to fool.”

We all have our jobs to do and have ways to do them successfully. Those systems are built upon a series of beliefs. Most of the time, we don’t have to worry about the underlying assumptions upon which are beliefs are built. We just do our jobs.

As Demosthenes and Feynman warn, the hardest thing to avoid is our own self-deception in thought. The commonly accepted ways of doing things might not be right. Those assurances from “experts” might not be based on rigorously-proven and tested underlying assumptions. The only way to know is to ask.

Takeaway: Every once in a while, seek out the skeptic or the Advocatus Diaboli, and ask “why?” And really listen.