I think it is time to redefine “belief”, or at least to limit its use a little. While it is true that the dictionary defines belief as “an acceptance that a statement is true or that something exists”, in many cases people seem to add “as a matter of faith” or “in spite of a lack of evidence”.
I don’t disagree with this amendment to the definition. This is why people believe in fairies, angels, demons and gods. I have no argument with this idea. My problem arises, along with my hackles, when perfectly rational people say they “believe” in evolution, the big bang, relativity or quantum mechanics. I think those who use the word in these cases do themselves a disservice.
Read some Fundamentalist Religious forum posts, or papers and debates arguing the case for intelligent design. One of the favoured chinks in the non-theist armour that the defendants of these world views aim for is our “belief” in scientific theories. They claim that believing in evolution is no different than believing in god; both take a similar measure of faith to uphold.
This is simply not true.
I have been guilty of saying I believe in our intellectual structures. Often, I have tried to defend my position against theists, and often I have been accused of engaging in so much blind faith. It was after one such skirmish that I realized: I don’t believe in evolution, I accept it as fact. I accept that this universe began in a massive explosion and inflationary period. I accept that life arose from inorganic chemicals that eventually benefited from an emergent ability to self-replicate. I accept that this replication led to life as we know it. I accept that life has changed, through pressure applied by natural selection, to better suit its environment. I accept that we humans share a common ancestor with chimps and other primates. I accept these things not through blind faith, but through the enormous edifice built by empirical evidence gained through scientific study.
As for more esoteric disciplines, I accept that quantum mechanics is the most complete description we have at this time to explain the behaviour of the very small, in the same way that classical Newtonian and Einsteinian mechanics describes the motions of the very large. I am intrigued by string theory, and by the multiverse hypothesis, though I recognize these ideas are still in their infancies (notwithstanding some interesting experimental data which may lend them much-needed support). I don’t believe any of these things, either. I have no faith in them, because I recognize they may very well be contradicted by new discoveries in the future.
I think we atheists, humanists and free-thinkers need to modulate our use of the “b”-word. By all means, apply it to things for which there is no empirical evidence. When it comes to scientific fact, though, try to use words like “accept”. It will help those who don’t share our views to realize we have very solid foundations and pillars around which to build our world views.