Science seeks certainty. The problem in medicine is, the body is complex and our knowledge is incomplete. People who want certainty – physicians or patients – are kidding themselves. And if we expect docs to be perfect, it’s a setup for dysfunction.

Sometimes I hear of patients who believe their physicians dissed a proposed or experimental treatment that’s not understood. (I’m not endorsing wacky treatments here – I’m only talking about uncertainty.) Yet, we’ve always had remedies whose actions aren’t understood; we just know they work. Even aspirin was used for a century without understanding it.

And here’s a line I read today: “Should I refuse my dinner because I don’t understand the digestive system?”

It’s by Oliver Heaviside (1850-1925), about whom Wikipedia says, “Although at odds with the scientific establishment for most of his life, Heaviside changed the face of mathematics and science for years to come.”

The quote is in the Pulitzer Prize winning book The Emperor of All Maladies: A Biography of Cancer, by Siddhartha Mukherjee MD. Emperor is cancer’s “whodunnit” story, centuries of efforts to understand it and treat it. And not in that order.

In the 1900s brutish early treatments (no more sophisticated than leeching) became more scientific. Inevitably some researchers then urged that we not try new treatments on humans until we know exactly what cancer is – basically, don’t move forward until we’ve got it figured out – with confidence. But meanwhile, people were dying.

As I wrote three years ago on my personal blog: “On the fringes of medical knowledge, lives are at stake and medicine doesn’t have the answers yet. What do you do?”

In my own case, my oncologist says there’s a 50% chance my disease will return, and there’s no way to predict which one I’ll be.

So we live, with uncertainty.

Participatory patients and physicians alike should accept that medicine is uncertain. Jerome Groopman MD’s excellent How Doctors Think even says 10-15% of all diagnoses turn out to be wrong, on autopsy. Fittingly, his epilogue it written to the (engaged) patient – how to discuss things anew with your doctor when the treatment isn’t working.

Science keeps pushing toward certainty, and disease doesn’t wait. Perhaps if we acknowledged the difficulty of diagnosis, and if more physicians were allowed and willing in our culture to express doubt, patient questions would be welcome and we could work more collaboratively.

By the way, the Wikipedia article on Heaviside has a different version of the quote: “I do not refuse my dinner simply because I do not understand the process of digestion.” Which to believe? Googling says the Wikipedia version is on 1,310 web pages and the book’s version is only on three.

What do you do in the face of uncertainty? How many sources do you check before you decide to move forward?

Dave deBronkart, also known as e-Patient Dave, blogs at e-Patients.net and is the author of Laugh, Sing, and Eat Like a Pig: How an Empowered Patient Beat Stage IV Cancer and Let Patients Help!