Much has been about science vs. faith. This quote by Tim captures one of the key differences.
Getting a religious person to define faith is difficult. When they try to discuss it rationally, cognitive dissonance sets in because they see how tenuous and irrational their faith is. Nevertheless, I believe that most people of faith would agree that taking steps to prevent a loss of faith is a virtue. C.S. Lewis defines faith in precisely these terms: "faith is the art of holding on to things your reason has once accepted in spite of your changing moods." What does "changing moods" mean? Our "moods" respond to our thoughts, which are driven by new observations. For example, I may read something about evolution, which gives me cognitive dissonance and affects my mood. Faith is what prevents me from taking the next step, i.e., questioning the basis for my initial acceptance of the objects of faith. What Lewis appears to be saying, therefore, is that faith prevents us from changing our minds when we make new observations. In other words, faith helps us to be closed-minded.
Science, on the other hand, is the opposite of faith. The essence of the scientific method is adjusting our hypotheses (or throwing them out) when conflicting new evidence is found.