Came across this quote the other day that floored me:
"Good sense is the most evenly shared thing in the world, for each of us thinks he is so well endowed with it that even those who are the hardest to please in all other respects are not in the habit of wanting more than they have. It is unlikely that everyone is mistaken in this. It indicates rather that the capacity to judge correctly and to distinguish true from false, which is properly what one calls common sense or reason, is naturally equal in all men, and consequently the diversity in our opinions does not spring from some of us being more able to reason than others, but only from our conducting our thougts along different lines and not examining the same things."
~~ Rene Descartes [Discourse on the Method]
Although I'm not a hufe Descartes fan, it is a great thought to ponder.