I have to agree with Alex on this- while it can be very interesting and even enlightening to discuss things with people, it is seldom useful to try to convince a sceptic. Any model has limitations and possibilities- some folks tend to focus on possibilities, some on limitations. Having sceptics around can be very helpful to possibility thinkers like myself.
So I have taken to listening with extreme curiosity, and rather than taking a position of someone being right or wrong, unraveling the mystery of what the other believes, how and why etc. I stay happily curious, learn alot, and the other person is happy that someone is trying to understand them.
Sometimes they are even willing to entertain my ideas in kind, sometimes I adjust my thoughts as well, but that does not realy matter, because understanding does not have to mean agreement. When one tries to convince another, it s not nearly as much fun- at least for me.
vitaman