[Paul Bloom] says “scientists take certain things on faith.” What he means by that is there are certain truths that science accepts that cannot be themselves scientifically proven. These would include things like the validity of the laws of logic, mathematical truth, the fact that the external world exists, the fact that the past is real and not an illusion of human consciousness, the fact that the world is so structured that science can describe and predict the way the physical world will unfold. None of these things can be scientifically proven. They are presuppositions or assumptions that scientists make. I don’t like the language of saying “they are on faith.” I would prefer to say that these things are properly basic for the scientific endeavor. — William Lane Craig (from, Scientific Faith)