My wife and I spend an occasional evening at a nearby restaurant with a piano bar—where she is regularly invited to sing. At times, we join the “patio people” for discussion, drinks, and an occasional cigar. While I usually get scarce when the topics turn to religion and politics, I recently hung around long enough to reflect on the notion of certainty. The first thing I noticed is that certainty often seems directly related to the amount of alcohol consumed. But, you’re not following my blog for such pedestrian observations.

People have beliefs or even convictions that cannot possibly be wrong. Their journeys toward their conclusions validate the internal sensation that something just is. If you believe you are unshakably right, it has to follow that those with an opposing viewpoint, at best, deny the truth, and at worst, attempt to lure others into their falsehood.

For some, being certain at times is more forceful than knowledge; it can involve being mistaken in high decibels. Paul Conrad, Political Cartoonist said of Charles Coughlin, a 1940’s radio preacher: “I knew that anybody who had to holler that loud couldn’t be right.”

We know from observing others, as neuroscience now validates, that the feeling of knowing is not a reliable indicator of accuracy. Our minds and brains can mislead us; social contagion and herd mentality can sway or even blind us.

Called “absurd” by Voltaire and “an intellectual vice” by Bertrand Russell, certainty can deaden imagination and derail empathy, our most humane and redeeming qualities. Our own certainty can make the stories of others inconsequential.

Freud had a self-fulfilling, circular certainty when he said that those who did not believe in psychoanalysis were simply “resistant.” In Psychiatry, pathological certainty is termed confabulation: to make up and believe information that fills in gaps of mind or memory—in the boardroom, it’s called a lie. Another brand of certainly is delusion: a fixed, false belief—in the consultation room, it’s called a diagnosis.

We have an aversion to uncertainty. Doubt creates an uncomfortable, insecure space. A series of studies by Dr. Dan Gilbert of Harvard showed volunteers words flashed on a computer screen for a few milliseconds. This was such a short time that each volunteer was unaware that the words were shown and could not pick them out—or guess—from a multiple choice. Yet they were influenced by them. For example, when the word hostile was flashed, for the next 30-45 minutes after viewing the word on the screen, volunteers judged others negatively. When the word elderly was flashed, volunteers walked more slowly. When these volunteers were later asked why they judged or walked the way they did, they immediately created an explanation. For example, the volunteers who walked more slowly would say, “I was tired when I did the test.” Or, “I’ve been traveling and haven’t slept well.” Each was unaware of the fact that they were falsely attributing cause and effect. But they seemed certain.

Our minds seek closure, and our brains strive to end dissonance by a causal explanation. To create a complete story infers both closure and a sense of effectiveness. Completion trumps accuracy.

Frustrated by “On-the-one-hand… while on the other hand…” advice of his monetary advisors, Harry Truman threatened to appoint a one-armed economist.

We sometimes defer to the patio philosopher who seems most certain, or the politician who radiates assurance. We often elect the ultra confidant to lead us.

Charles Renouvier said it most insightfully, “Properly speaking, there is no certainty; there are only people who are certain.”