Harris believes that certainty is a false goal.

Question: Is there certainty in science?

Sam Harris:  Certainty is, I think, a false goal.  I mean we’re not achieving . . .  We’re achieving functional certainties in science and in just . . . in our day-to-day lives.  I mean it’s a functional certainty that I’m sitting here talking to you, though it’s possible I could be dreaming or, you know, deceived by an evil demon.  Those kinds of philosophical, ______ worries don’t really relate too much to the ordinary practice of science, the very useful practice of science, and our ordinary task of just negotiating our lives and finding happiness in this world.  We recognize that there’s a range . . . that there’s a continuum of, “I’m not sure, there’s a coin toss, fifty-fifty” understanding of a circumstance to being functionally certain about what is so.  And many people are pretending to be functionally certain, or believe themselves to be functionally certain about things like Jesus is gonna come back and judge the world in their lifetime.  Twenty percent of the American population claims to be functionally certain that that is gonna come to pass, and 78% think that Jesus is gonna come back sometime – not necessarily in their lifetime.  And these certainties do real work for us.  I mean the person who is certain that the soul enters the zygote at the moment of conception is the person who wants to veto stem cell research, despite the fact that tens of millions of people are suffering from conditions for which stem cell research is the best line of research to generate therapies.  So these are ideas that are not just of academic interest, or person, private, or spiritual relevance.  I mean these are shaping policy.  They’re shaping a national conversation.  And then when you look to the Muslim world, they are causing people to blow themselves up on street corners.

Recorded on: July 4 2007