THE BEST PHILOSOPHY IS DOUBT

The Big Question: Colin Blakemore is in favour of a philosophy that always asks if you could be wrong

From INTELLIGENT LIFE magazine, May/June 2013

Let’s face it, René Descartes isn’t the most fashionable of philosophers. All that mumbo-jumbo about ghosts in the machine doesn’t fit with current hardnosed views of the mind, which see it as more like a machine in the machine.

But boy, could René write! His “Discourse on Method”the first piece of serious philosophy that I ever readopens with this wonderful statement: "Good sense is the most evenly shared thing in the world, for each of us thinks he is so well endowed with it that even those who are the hardest to please in all other respects are not in the habit of wanting more than they have."

Descartes was right: people don’t like to admit that they are wrong. But he had a revolutionary idea—"never to accept anything as true that I did not know to be evidently so".

This was Descartes’ principle of doubt. It led him to disbelieve anything but his awareness of himself as a thinking being. Cogito ergo sum. That logic led him to some decidedly odd conclusions: but there’s still something to learn from René’s doubts.

Sciencethe method that underpins what we know most reliably about the world and ourselvesrests on uncertainty. The late, great Karl Popper argued that the only thing that can be definitively proved by an experiment is that a hypothesis is wrong.  Scientists always express, or should express, their ideas in terms of uncertainty. Remember the historic announcement last year that CERN had discovered the Higgs Boson? What they said was: "We observe in our data clear signs of a new particle, at the level of 5 sigma". What’s that 5 sigma business? It’s a statistical measure: it means that there’s a 1 in 3.5m chance that the most important discovery in particle physics in the past 50 years is wrong.

I’m not saying that scientists wake up each morning driven by the passion to prove that their ideas are flawed. We all hope that our theories are 5 sigma. But we have to live with the only certaintythat our opinions could be wrong.

Contrast that with the expectation that most people have of their leaders. The hallmark of charismatic politicians is that they have absolute confidence in their opinions. Politicians who change their minds on the basis of evidence are accused of U-turns, rather than being hailed for their wisdom. But unwillingness to doubt has given the world most of its political disastersfrom Darius’s invasion of Greece to the present adventures in Iraq.

Doubt is the engine of intelligence. We suffer from a surfeit of certainty. The most powerful philosophy is always to ask whether there is a possibility that you are wrong.

What do you think is the best philosophy? Read Jesse Norman on Aristotle, mashed up, Angie Hobbs on Plato's idea of flourishing, Anthony Gottlieb on Hume's scepticism, Simon Willis on particularism and Susie Orbach on self-knowledgeVote now in our online poll

Colin Blakemore is professor of neuroscience at Oxford and director of the Centre for the Study of the Senses in London. On May 26th he will speak at the Hay Festival of Philosophy and Music in two sessions: "Beyond the machine" and "Catching sight of ourselves" 

Illustration Neil Gower