Rationale is an interesting program that allows you to visually represent arguments:

It is essentially a domain-specific Visio or MindManager. Since it is domain-specific, it is faster to construct a complex tree and additionally export the structure as a text outline. This also limits it a little, in that I couldn't find a way to associate a single point with multiple higher-level positions ("Ruby is easy to learn" relates to both training developers and maintenance). While it could be argued that one should continue to decompose one's arguments until they fit into a neat hierarchy, that seems a little over-zealous for the general case. (Incidentally, I didn't use the product to structure this paragraph, but it turned out quite close to the sort of text generated by Rationale.)

It's fun to use and you can rapidly construct arguments either top down ("We should use Rails for our next application" because ... ) or bottom-up ("Ruby's interactive console allows active exploration" supports ... ). It does not attempt to parse your logic (it won't balk at "because I say so") but it can help structure an argument for conversation and review.

As long as everyone agrees that decomposition is a productive route and as long as people aren't so cagey that they recognize that structuring a debate is 3/4 of the way to winning it. That's my biggest problem with the product; at $199 for a perpetual license or $100 per year, it's a little pricey for something I don't think you'll be using in many meetings. However, as an educational tool, I think it's a good bargain. The educational rate is $49 for a perpetual license or $24.50 annually, and I think this would be a very good tool for students learning rhetoric, debating, logic, or composition.

You can download a 30-day trial version from Austhink.