This widespread misapprehension that atheists believe in nothing positive is one of the main reasons secularly inclined Americans — roughly 20 percent of the population — do not wield public influence commensurate with their numbers. One major problem is the dearth of secular community institutions. But the most powerful force holding us back is our own reluctance to speak, particularly at moments of high national drama and emotion, with the combination of reason and passion needed to erase the image of the atheist as a bloodless intellectual robot.

The secular community is fearful of seeming to proselytize. When giving talks on college campuses, I used to avoid personal discussions of my atheism. But over the years, I have changed my mind because such diffidence contributes to the false image of the atheist as someone whose convictions are removed from ordinary experience. It is vital to show that there are indeed atheists in foxholes, and wherever else human beings suffer and die.

Now when students ask how I came to believe what I believe, I tell them that I trace my atheism to my first encounter, at age 7, with the scourge of polio. In 1952, a 9-year-old friend was stricken by the disease and clinging to life in an iron lung. After visiting him in the hospital, I asked my mother, “Why would God do that to a little boy?” She sighed in a way that telegraphed her lack of conviction and said: “I don’t know. The priest would say God must have his reasons, but I don’t know what they could be.”

Just two years later, in 1954, Jonas Salk’s vaccine began the process of eradicating polio, and my mother took the opportunity to suggest that God may have guided his research. I remember replying, “Well, God should have guided the doctors a long time ago so that Al wouldn’t be in an iron lung.” (He was to die only eight years later, by which time I was a committed atheist.)

The first time I told this story to a class, I was deeply gratified when one student confided that his religious doubts arose from the struggles of a severely disabled sibling, and that he had never been able to discuss the subject candidly with his fundamentalist parents. One of the most positive things any atheist can do is provide a willing ear for a doubter — even if the doubter remains a religious believer.