A great deal has been seen and heard lately of Jews bashing Jews, much of it laced with irony in that it has been perpetrated in the cause of solidarity. Often driven by an impatience with the establishment - so that the leaders of the Board of Deputies especially have been getting it in the neck - it seems to be in parallel with the force that has propelled Ukip into political prominence.
It has gone beyond polite differences of opinion and concern has been expressed about the level of personal abuse involved. But it has largely been in-house, communal sparring.
Over the past week or so, however, the Jew-bashing-Jew phenomenon has become more sophisticated. Emanating from individuals far too mature to descend to abuse, it is nevertheless personal, one-to-one stuff - and it has extended well beyond the communal sphere.
Maureen Lipman, writing in Standpoint magazine, has told Ed Miliband that, on account of his attitude towards Israel, he has single-handedly broken her lifelong attachment to the Labour Party.
In the Independent, Lipman's fellow Israel defender Howard Jacobson berated Miriam Margolyes for calling Israel stupid, "for allowing people to vent their antisemitism".
Let's stop worrying about Jews bashing Jews
"Try that argument in cases of sexual abuse," counters Jacobson. "Try saying you shouldn't have given your assailant the opportunity to vent his violence against you."
Neither Lipman nor Jacobson used the "as a Jew, Miliband/Margolyes ought to know better" line of argument but many who endorse their views certainly will. And there will be many of their Jewish, Israel-condemning opponents who will use the "as a Jew, I…" line to claim a special entitlement to air their views.
The latest Gaza conflict and its ramifications have brought all this to the boil. It has been hard, in the face of relentless and vicious opprobrium heaped upon Israel - rapidly extended towards Jews in general - not to make a blanket response. Unfortunately, that's the way argument over Gaza, Zionism and antisemitism has developed.
It's become gung-ho, good and bad, right and wrong - if you are a Jew, you must give total, unequivocal support to Israel; if you're from the BBC, you must be biased.
But it shouldn't take too much reflection to appreciate that Israel has been maligned and threatened and that Palestinians have also suffered injustices.
It does no group - least of all Jews - any favours to be lumped together as one. These are not monoliths but human beings of varied views, dispositions and experiences.
The case against Israel is best rebutted on grounds of justice, not by trading invective. By solid evidence, not unexamined assumptions.
Likewise the case for Zionism, and that against bigotry, ignorance and antisemitism - all of which can be exposed for what they really are by figures of the stature of Jacobson and Lipman. Since Gaza, we have been swayed too much into treating complex issues as slabs of black and white.
So let's not worry too much about these Jews bashing Jews. It is sometimes salutary to do the dirty washing at the public laundry.
It's one way to show the world that there are big Jews and small Jews, loud Jews and quiet Jews, Labour Jews and Tory Jews, smart Jews and stupid Jews, sober Jews and drunk Jews, apple Jews and orange Jews … and, yes, black Jews and white Jews.
