By Tom Ehrich

Anti-Semitism is only one form of irrational hatred. But it seems a helpful barometer when clouds of insanity and rage are gathering.

In recent years, Russia's tsar stoked anti-Semitism as a diversion from his rapacious and stupid behavior. So did the communists who ousted him.

The Klan lumped Jews and blacks into a potent scapegoat for poor whites' troubles -- troubles actually being caused by rich whites. Hitler rode to power on hatred of Jews. Relentless campaigns against Jews and their nation Israel help radical Islam avoid accountability.

Now French Jews are said to wonder if France can remain their home. The zest with which French people persecuted Jews under Nazi rule apparently didn't answer that question 75 years ago.

As outcries against Jews cascade into public awareness, we should be asking how insane and hateful today's people have become. When a tiny band of scattered souls can stir this much hatred, something fundamental has gone off the rails.

It makes me wonder whether we moderns are just barely holding on. I like to think we are solid, but then teenagers bully classmates, fraternity men rape their dates, state legislators ban anything that might benefit homosexuals, conservative politicians declare war on basic "neighborliness," as one blogger put it, and plot to deny living wages, decent health care, effective education, scientific advancement and basic dignity to their fellow Americans.

Any one of these might be passed off as a blip of nuttiness and meanness, but taken together, they suggest a groundswell of insanity and rage -- all of it quite self-defeating from a practical standpoint and quite immoral from a religious standpoint.

What do we think is going to get better if we marginalize homosexuals, reverse women's gains, punish the poor for being poor, promote ignorance, or make people sick? There's no rationale behind any of this. That's why I call it insanity.

The consequences will be immeasurably harmful, not just to the targets of our rage but to all of us. Even the precious few who think themselves magnificent winners are playing a suicidal game.

The era that seems pertinent is the witch-hunt insanity that took over Massachusetts in 1692 and 1693. A major cause of that mass hysteria was religious extremism, as is much of today's insanity.

Those of us who labor in faith's vineyards have work to do. Not to grow our franchises or demonstrate our right-opinion, but to promote neighborliness by acting it out and to nurture communities of sanity.

We aren't the only culprits. But we are unique, in that we should know better.