XKCD says, "Science doesn't ask for your faith, it just asks for your eyes". Phil Plait of Bad Astronomy exults in scientists' fact- and experiment-based approach to life. The popular image of science is of something that's based firmly in fact, that doesn't require faith to see the objective state of the world.
I say otherwise. Here's three quick areas where, to believe in science's conclusions, the ordinary person has to have faith:
Faith In That Which Is Beyond Me
I have no choice, if I want to believe in science, than to believe in a body of knowledge that I will probably never see and couldn’t understand even if I did. I take it on faith that Stephen Hawking wrote a paper somewhere sometime that says black holes exist. If you actually asked me to read it and understand his arguments, I wouldn’t be able to. Faith is required. This holds for scientists, too, in different disciplines; a marine biologist probably can't explain astrophysics, and vice versa. Be you a scientist or a lay person, you rely to some extent on the conclusions of others in understanding the universe, which means that you have to have faith in their honesty, transparency and reasoning abilities.
Faith In That Which We Have Already Discovered
There has to be faith that our universal laws will hold anywhere. Bill Anderegg, who I interviewed for a global warming note awhile back, explained it to me this way: We could argue forever over whether the data indisputably, beyond the slightest particle of doubt, show the planet to be warming up. But at some point when there’s a reasonable level of consensus, we have to be able to look at our results and say “Okay, we think this is good. Now we can extrapolate from these results and build on what we’ve found.” We have to have a certain amount of faith in what we’ve already discovered, be it universal laws or the pattern of spots on the bellies of East African toads, so we can build on that data and move onto the next thing. That’s faith, faith in our own discoveries, faith that they hold everywhere and all the time. If we didn’t believe that the luminosity of a star is proportional to the (temperature to the fourth power) times the (radius squared), every single place in the universe, we wouldn’t be able to draw any kind of conclusion from the stars. As it said in my physics textbook, we have to take it as a given that the laws of physics hold everyplace, and that, too, requires faith.
Faith In You, Me and All Of Us Together
You may have seen where I’m going with this third one based on the second one, as the second one is really a consequence of the third one, but whatever, it sounds better if I put this one last. The last thing we have to do is to believe in ourselves. That’s the biggest difference between religion and science. Religion asks us to believe in some external entity. I’m speaking from a predominantly Jewish background, and my culture is speaking from the Abrahamic tradition through me, but it doesn’t take a rabbi or a Thai monk to realize that all religions around the world believe in some higher power than humanity (with the possible exception of Animism). Whether it’s God, Jehovah, ancestral spirits, the spirit world or what, religion looks to the heavens for guidance and trusts that, by that guidance, the world will make sense.
But here’s why if I had to choose I’d go with science over religion: science asks us to believe in us. We’re supposed to believe that we—little dumb hairless apes that we are--have the capability and capacity to understand the world and the laws that make it up. We have the temerity to say that we can understand this huge, implacable, incredible, beautiful universe. And you know what science says to that? “Fuck yeah, we can.” Science tells us to believe in ourselves and in the whole human race, and in our ability to make the world make sense. And I believe the shit out of that philosophy.