We often talk about ideas by using phrases like "I believe X." But what do we mean when we say that we "believe" in an idea? Do we mean that we have 100% confidence that the idea is true? Let's hope not. Even statements that we all would say we very strongly believe, like "tomorrow the sun will rise", and "I am not a robot" we should not assign 100% probability to. While we can be very, very, very certain that the sun will rise tomorrow and that our brains are not computers, we cannot be abso...