The comedian Louis C.K. has a smart routine about the ugly thoughts we all tend to think but, out of good sense and civility, tend to suppress. He calls this way of thinking “of course but maybe,” and it goes like this: First you think, “Of course, of course slavery is the worst thing that ever happened.” And then there is that part of your brain that thinks, “Of course, but maybe. Maybe every incredible human achievement in history was done with slaves.” The pyramids. The transcontinental railroad. Even our iPhones.

“Everybody has a competition in their brain of good thoughts and bad thoughts,” he says. “Hopefully, the good thoughts win.”

Last month Rabbi Steven Pruzansky of Teaneck wrote a blog post (since deleted) containing a series of bad thoughts. Titled “Dealing with Savages,” his post proposed that there is “a war for the land of Israel that is being waged, and the Arabs who dwell in the land of Israel are the enemy in that war and must be vanquished.” Among his proposals for vanquishing this enemy: destroy entire Arab villages and expel their residents if a terrorist comes from them. Shoot rioters and stone-throwers with live ammunition. Bar Arabs from the Temple Mount for at least six months. “Perhaps,” he writes, “the day will come in the near future when the mosque and the dome can be uplifted intact and reset in Saudi Arabia, Syria, or wherever it is wanted.”

Responding to criticism from the Orthodox Union and the Rabbinical Council of America, among others, Pruzansky walked his comments back, but only slightly. The “savages” in the title was meant to refer only to terrorists like those who carried out the Nov. 18 massacre in a Har Nof synagogue and was not meant to apply to all Arabs or Muslims, he wrote.

Nevertheless, the denunciations were swift and angry, many from liberals but also a good number from religious and right-wing Jews who usually share Pruzansky’s band on the ideological spectrum. “We cannot countenance a response to terror that resorts to wholesale demonization, advocates for the collective punishment of Israeli Arabs, or calls for the destruction or dismantling of Muslim holy places. Such rhetoric is anathema to the Jewish religious tradition and has no place in civil society. Such rhetoric is wrong and must be repudiated, whether it is voiced by lay leaders, community leaders or rabbis,” the Orthodox Union said in a statement referring, obliquely but unmistakably, to Pruzansky’s “Savages” post.

Pruzansky is a serial provocateur who has written similarly inflammatory essays about Israeli doves and even his own colleagues in the Orthodox conversion process. He is not a national figure, nor is he an Israeli politician (nor, for that matter, does he live in Israel). He does lead the largest synagogue in the Modern Orthodox bastion of Teaneck, and his ideas reflect, judging by the positive comments on his blog and his long-term tenure at his synagogue, a healthy portion of his own right-wing constituency. The hearty “amens” to his blog said he was writing a truth both Israel and America refuse to acknowledge — a common trope of the anti-Islam blogosphere and some far-right pro-Israel activists.

More interesting were the responses of the “of course but maybe” variety, on Facebook and elsewhere. They went like this: Of course Israel should respect human rights and Western norms of behavior. Of course all Muslims aren’t savages, and Israel is not at war with its own Arab citizens nor with the Palestinian people of the West Bank, East Jerusalem, or Gaza.

But maybe harsh times call for harsh measures. But maybe savage attacks like the one that killed four Jewish worshipers and a Druze policeman in Jerusalem need to be met with equally savage retaliation. Maybe that’s the only language “they” understand.

I’m hearing “of course but maybe” thinking wherever Jews gather to discuss the crisis in Israel. Of course Israel needs to be a democracy, but maybe it is more important to enshrine a degree of inequality in order to preserve the Jewish character of the state.

Of course we believe in the two-state solution, but maybe its time has passed and an indefinite occupation is less risky than a dangerous peace process.

Of course Israel should be proud of its robust human rights NGOs, but maybe these groups play into the hands of Israel’s enemies and need to be reined in.

(You hear it on the other side too: “Of course terrorism is immoral, but maybe the Palestinians have no other way of pressing their cause.”)

“Of course but maybe” is a comforting formula because it lets you express your humanity and tolerance, while suggesting humanity and tolerance may be luxuries in these troubling times. You get to have it both ways: You can air illiberal or even repugnant thoughts while reassuring your listeners that you understand the difference.

But poisonous thoughts tend to become unthinkable actions when good people don’t speak up for democracy, tolerance, and the rule of law. Leaders can empathize with anger, but need to govern from a place of circumspection. They need to weigh the thoughts that satisfy our passions against solutions that will actually prove practical, and defensible, in the real world.

Hate and anger are understandable and satisfying emotions when someone attacks a member of your extended family, or your national enterprise. Who doesn’t recoil at footage of Palestinians celebrating the deaths of Jewish innocents, or Palestinian mothers praising their terrorist sons and daughters as “martyrs”?

If we didn’t react in anger to provocations like these, we’d lose our right to be called human. But if we don’t temper that anger, we lose our humanity.