Consider empirical skepticism: a high standard for physical evidence before committing to a belief. One might be tempted to think that this means “I’ll believe it when I see it.” Strangely, this is not the case. Example: A few short centuries ago, doctors “saw” imbalanced humors and bad vapors, and they “saw” people cured when those conditions were relieved. The “evidence,”confirmed their incorrect theories because it was limited and not properly examined. Skepticism was the idea that maybe the deductive reasoning from the theoretical premises of the day (four Aristotelian elements, humors, etc.) might be flawed because the theories were affecting the perceptions of the outcome.
Skepticism said: “Don’t trust your eyes. Trust the data.”
Modern surgical technique was developed by Joseph Lister who reportedly said “it’s as important to wash your hands before surgery as after.”
Think of how radical that is! It is tantamount to saying “don’t trust what you can see. I know you can’t see the thing on your hands that will kill your patient. I don’t even know what it is. Some Frenchman named Pasteur thinks maybe he’s on to something about that. Look, just trust my blind data that tells me that more people survive surgery if I wash my hands.”
We fancy now that it’s so obvious that there are these invisible things called “bacteria,” that anyone with any sense would figure that out from a few simple observations and “common sense.” Quite the contrary. As a doctor or a researcher, it is critical to remember that your conception of the world changes your perception of the world. The data is the only thing that will tell the truth, and it will only tell you the truth insofar as you ask the right question with your experiment.