Hack:
Engage feedback

Old management practices have stunted people's ability to discuss ideas.  Often, when we discuss our ideas with others, we tend to defend them and try to convince others of our brilliance.  An alternative strategy, more open source, is to simply tell your peer that their comment is very interesting and ask them to say more.  "Have you thought about....?"  "That's interesting, say more.  What are you thinking?"  You don't need to agree or disagree with any of the feedback.  But the more you get and the more diverse the feedback, the better informed you'll be when you go make your idea better!

This completely changes the dynamic of the conversation and actually builds momentum for what you are doing.  Try it.