Real debate (as opposed to presidential clown shows with eight people on a stage offering 15-second sound bytes in responding to the most complicated problems of the day) serves the public better than any other form of public discourse, here's why: when there are two or more intelligent advocates of differing positions, each in command of the relevant data, it becomes impossible for one side to reduce the other to a caricature.
Lectures can be great - but when a speaker addresses a contentious issue without knowing he/she is faced with an informed opponent the temptation to dumb down the opposing argument is strong. Having an opponent standing ready to drop the hammer on factual inaccuracies, distortions and simplifications imposes a rigor that delivers far greater value to an audience that wants to do more than just affirm the opinions it came with.
Trevar and I saw a lot of this at the Battle of Ideas, and partners like the Institute of Ideas are helping make FORA.tv the destination for people who want to explore ideas, challenge their own assumptions and get informed in the process.
