When fact and faith conflict, how do we move forward?  We usually don’t. A much-cited Oct. 2006 Time magazine poll showed that 64 percent of Americans would “hold on to what their religion teaches,” even in the face of scientific evidence.  In the 1980s, two Arizona State physics faculty showed that students didn’t learn from physics labs that contradicted their day-to-day experience. “As a rule, students held firm to mistaken beliefs, even when confronted with phenomena that contradicted those beliefs.” And we all have a friend who just knows the moon landings  were faked.

One particularly troubling, but common belief is that pharmaceutical companies and public health officials are hiding the fact that vaccines cause autism, a conspiracy theory that many cling to,  despite mountains of data showing no connection between the two (and no convincing evidence to the contrary). But there are anecdotes, lots of them. You don’t have to look very hard to find empathetic stories from grief-wrought parents claiming that the MMR vaccine—or mercury, or formaldehyde, take your pick—changed their child.  Or, as Jenny McCarthy puts it, “The light left his eyes.”

The fact that autism’s most visible signs occur in the same period when children receive the bulk of their life-saving vaccines becomes,  for these parents, evidence of cause rather than what scientists rightly call correlation.  This conspiracy theory survives the strongest kinds of repudiation.

It turns out that Andrew Wakefield, the British doctor who first published reports suggesting the link between autism and vaccines, faked data for his article, which he wrote on behalf of lawyers hoping to sue the vaccine manufacturers. When scientists removed the supposed cause of the epidemic, thimerosal, autism rates continued rising. Then conspiracists shifted their claims—it must be something else in the vaccines.  Even as preventable diseases like measles and whooping cough make a comeback,  and study after study fails to find any credible evidence of harm, anti-vaccination forces continue spreading the same misinformation.

I’m interested in the way these beliefs endure. Why do we cling to faith in the face of controverting facts? Perhaps it’s because we often perceive faith as fact. Everyone has strong vested interests with the debate over vaccines. Most of the anti-vaccine advocates innocently, but wholeheartedly,  believe their arguments; we on the other side hold our views just as deeply. When humans strongly believe something, we no longer distinguish it from fact. We believe in both God and ice cream.

But the secret at the heart of the Enlightenment was a shift in that faith,  away from faith in facts toward faith in method.  To “believe” in science is not to believe that the Earth is round, that Neil Armstrong walked on the moon or that we came from monkeys. It’s to believe in shared facts, verifiable evidence and the most convincing explanation of these.

It’s strange to espouse a faith in a system that could shift worldviews overnight, but I take comfort in it. We’re a species who looked into the heavens, and by the shifting of the stars above, we came to better understand our place in the universe. Then we turned those telescopes inward to discover entire universes inside.

We have only been able to do that because we understand that we interpret what we see, hear and experience, and that our interpretation can be wrong. We’re at our best when we put faith not in a specific view of the world, but in how we know which view to believe.

Brendan Riley is an Assistant Professor of English who teaches writing, new media and popular culture courses. He has faith in facts.

briley@colum.edu