As Voltaire remarked, “Doubt is not a pleasant condition, but certainty is absurd.”

The problem is that certitude seduces us. It enables us to believe that what was said to be true is true because someone else said so. It simply cuts off thought. It arrests discussion in midflight. And yet we yearn for it with a passion. We spend endless, sleepless nights grappling with intellectual options in order to wiggle them into a satisfying kind of certainty without so much as a scintilla of evidence.

Rulers of all stripe and type dispense certainties—theirs—with great abandon. They do whatever it takes—define cultural dogmas, assert organizational doctrines, impose decrees, and use power, force and penal systems—to suppress the ideas of anyone who dares to question them. Ideas, after all, are dangerous things. Ideas have brought down as many myths and mysteries as they have toppled kingdoms.

But there is another way to live that runs hot and bright through darkness. There are always some in every population who know that life is not meant to be about certainty. Life, they realize, is about possibility. They see certitude as a direction but not an end.

Doubt is what shakes our arrogance and makes us look again at what we have never really looked at before. Without doubt there is little room for faith in anything. What we accept without question we will live without morality. It is in populations like this that monarchs become dictators and spiritual leaders become charlatans and knowledge becomes myth.

An ancient people tell the story of sending out two shamans to study their holy mountain so that they could know what their gods expected of them. The first shaman came back from the north side of the mountain to tell them that it was covered with fruit trees, a sign that their god would always bless them abundantly. The second shaman came back from the south side of the mountain to tell the people that it was barren and covered with rock, a sign that their god would always be with them but intended them to take care of themselves. So, which shaman was right? If both, then it is dangerous to dogmatize either position.

It is doubt, not certitude, that enables us to believe, because it requires us to think deeply about an entire subject, and not simply depend on the side of reality that is on our side of the mountain. Only when we look beyond absolutes to understand every level of life can we possibly live life to the fullest, with the deepest kind of insight, with the greatest degree of compassion for others.

Voltaire was right, of course. Certainty is comfortable but always unlikely and forever disruptive. As life changes so must our explanation and response to it.

—from Between the Dark and the Daylight by Joan Chittister (Penguin Random House)