I am constantly amazed at the number of time on this forum that I run into questions (or statements) that involve the concepts of "proof" or "absolute certainty". It occurs to me that some of us "have to know for certain" about things that others here consider "unknowable". So, I pose these questions: How comfortable are you with doubt?. Does your "belief system" involve "black and white truths", or "shades of gray"? Whichever you choose, do you know "why" you are the way you are? Do you consider "certainty" a strength? a weakness? something else?