Unless you could do addition and subtraction, it’s unlikely you’d be able to do multiplication. There’s a certain progression to things. And if we don’t understand that, we move forward not because of understanding things but because of ignorance and arrogance. Ignorance and arrogance combined take you to places where angels fear to tread. We need to be able to see the limitations of where the actual knowledge that we have at a certain point in time takes us. And one of the most important things for us to understand is what we don’t know. If we are constantly content with what we think we know, then there’s no impetus to take us any further.