Self-doubt is essential for scientists and inventors. Doubt helps us avoid mistakes. Doubt leads us to discoveries. Unfortunately, it’s easy to say we constantly question our own beliefs--and hard to do.
People try to convince themselves and others that they are healthy skeptics merely because they question and challenge other people’s ideas. Sorry, but that doesn't fly. It’s easy to doubt ideas in which we have little if anything invested. A genuine healthy skeptic challenges his or her own convictions and leanings, and does so repeatedly.
I just finished reading The Pleasure of Finding Things Out, a compilation of speeches and other short works by the American Nobel Prize winning physicist Richard Feynman. The importance of being skeptical is a recurring theme in the book. Some of my favorite quotes from Feynman on the subject are:
"The first principle is that you must not fool yourself - and you are the easiest person to fool."
"I believe that a scientist looking at nonscientific problems is just as dumb as the next guy."
"…I can live with doubt and uncertainty and not knowing."
Specifically, Feynman said that it’s important for scientists to report all of the details of their investigations, highlighting areas of uncertainty. (Yes, even scientists tend to "spin" their results.) And when following up on recent research by others, they should carefully repeat the original experiments. In Feynman’s view, there is a continuum of certainty. At one extreme is complete doubt, and at the other extreme is complete certainty; science always operates between these extremes. Scientists like to give others the impression they deal with absolute certainty, but that's not true.
I encounter many people who say they are skeptical thinkers, but I encounter very few people who really live by the ideas above. In fact, I see people proudly displaying a distinct lack of skepticism.
For example, I often hear scientists say “We now know (fill in the blank).” What they should say is “We now believe…” or “We now think we know…”
As America’s second greatest inventor (after Thomas Edison), Edwin H. Armstrong, was fond of saying “It ain’t ignorance that causes all the trouble in this world. It’s the things people know that ain’t so.”
We tend to reduce any topic we are investigating to a few key facts and principles. It helps us to get our arms around the issues. Unfortunately, there is inevitably some loss of information. The lost information doesn’t seem crucial at the time, but it often becomes important later. That's why it's necessary to remain vigilant.
Apply this thinking to controversies such as global warming, intelligent design, superstrings, and health care reform. I'm not suggesting that the accepted view is necessarily wrong. Nor am I saying both sides are partly right. But we should recognize that our own positions are never completely unassailable, that the other person’s position may have merit we have overlooked, and that as healthy skeptics we should be willing to revisit ideas supported by people who are otherwise intelligent and reasonable—no matter how wrong we previously thought they were.
Note: several changes (including the title) were made Dec. 9 to clarify this post.