Discussions lose an awful lot when they degenerate into debates.

In a debate we argue for a predetermined position, and set out to overcome the other side, scoring debating points along the way. The aim is to win. Enjoyable enough as a sport.

In a discussion we try to explore points of difference, looking for points where people actually agree, and try to build on that. The aim is greater understanding of the way other people see things, and greater understanding of what we actually believe, which may get modified in the process.