Certainty, that thing of indefinite approximation

Certainty is not what it used to be. Our ancestors had the certainty of their gods, myths and rituals, then of one God, his purposes and the orderliness of all that he had created. The Enlightenment promised a world freed from the lore of the past by the power of human reason; the industrial age, a world endlessly made better by the force of Progress. Few such absolute certainties survive in the twenty-first century and yet, it seems, we cannot resist the urge to cling on to the old ones, or to fabricate new ones. Why is this so? Certainty, that thing of indefinite approximation pieces together answers from an original and sometimes startling mix of sources, ranging from religious and philosophical texts to memoir, fiction and popular science. While acknowledging the truth of Jean-Paul Sartre's observation that many of us prefer to be 'massive and impenetrable' because we fear uncertainty, the essay concludes by suggesting that we would live better with ourselves, and with each other, if we could learn to tolerate John Keats's notion of 'being in uncertainties'.