The debate goes back and forth. Should Columbia University have invited Ahmadinejad to speak, even given the fact that the University's president attacked him? Many issues enter into the debate. One is the question of freedom of speech. Does freedom of speech not allow one to present even the most grotesque concepts (as long as it does not actually lead to violence) for if you put any limitation of this freedom it will eventually swallow all disagreements? But that really was not the issue. The further question was really whether the university should have invited him. Freedom of speech may ultimatlely allow someone to speak but that does not mean that I have to provide this person with a forum.
That , though, was also not the real question for Columbia also recognized that it had no obligation, under the concept of freedom of speech to provided this forum. So the further question is why did Columibia provide the forum? The cynical answer would be that it served Columbia's self-interest however the university's president contended that, since it was a controlled environment, it provided the opportunity to challenge and critique Iran and the Iranian president. So that becomes the real question -- is it better to challenge evil head on in debate or is it better to ignore it? Should Ahmadinejad had been offered a forum given that this forum will also provide the opportunity to call him a petty and cruel dictator or is it better to ignore him? That is really a most interesting question.
The history of the Christian-Jewish debates of the Middle Ages would seem to support the latter view. Torah scholars clearly attempted to avoid these disputations and, as greatly evidenced by the Disputation between Ramban and Pablo Christiani, the result of these disputations was negative even as the Jewish scholars clearly one the academic battle. But in these cases, the environment was shaped to ensure this negativity. Perhaps in more objective circumstances, Torah scholars would have been more open to a forum which allowed the expression of the divergent opinion knowing full well that the result would be positive and lead perhaps to a better outcome. Afterall, does Pirkei Avoth not say to know how to answer the heretic and did not members of Chazal find themselves in situations whereby they debated heretics, or at least answered them. Still there is s great difference between responding to the challenge of a debate and inviting one like Ahmadinejad to speak.
The problem is that once you give a forum you never know what the response will be. Already I have heard that in Iran the invite to Columbia has been given a totally positive spin without mention of how the attack on Ahmadinejad. Alternatively, I have heard that there have been criticism of the U.S. and how rude this country is, without mention of the substantive issues mentioned by Columbia's preseident.
There is a side of me that still believes that the best way to fight evil may be by placing it out in the open and then showing it for what it is. The potential ridicule of evil through substantial debate may have great value. But there is a great but. The circumstances of debate ultimately rule the debate. The problem with Columbia's theory may be that you cannot control the circumstances and the environment. That was the great ultimat lesson of the Ramban's disputation with Christiani. Ramban really tried to level the playing field, ensure an objective debate. It sadly didn't help because the other side found a way around it and used the very disputation that they lost for their own benefit. In the end perhaps ignoring is the practically best way.
The issue thought is a real one.