There are two things we desperately need to talk about – the availability of guns and the failures of our mental health systems. We can't seem to talk seriously about either one, but for different reasons.
With guns, it's because of the polarization over the issue. On one side are gun-control fanatics who assume guns can be willed away – that somehow strictly controlling them won't further embolden criminals and weaken honest citizens. On the other side are gun-rights fanatics who treat every attempt at regulation, however modest, as a vicious threat to the fundamental rights of all. Because those two groups talk past each other, we never get to the real issue, which is that it is far too easy for people who shouldn't have guns to get them. Surely we all hope that when people such as Lanza get their murderous impulses there isn't a deadly weapon handy. How can we keep such people from getting guns without depriving us all of our rights?
With mental illness, it's because we're afraid to talk about the subject at all, because those who suffer from it remain the most stigmatized people in America. But there are dangerous people with mental afflictions who need help but don't want it. We must talk about helping them anyway, even if it includes some amount of involuntary detention. How do we identify such people, and how do we help them against their will? And how do we do that without further stigmatizing the vast majority of those with mental illness, who are no more of a threat than people without mental illness? As with the gun issue, the trick is to find the balance between the rights of the individual and the need for public safety.
Finding such balance won't be easy, but the effort is imperative. Only if we make the effort will we ever get to the crux of the matter, which resides at that point where mental illness and access to guns intersect.