"I never learned from a man who agreed with me." ~ Robert Heinlein
I recently read a biography of Ayn Rand who I consider an inspiration for many of my ideas and I was very disturbed by the cultist nature of her life in the later years when she would break up friendships over the slightest disagreement about politics, philosophy even art. For me I have always, as Heinlein said, learned a great deal from those who disagree with me. Respectful discourse of disagreements is not only more educational but, I think, more fun that discussion with someone who agrees completely with you.