Born to an unremarkable Jewish family in Germany, Moses Mendelssohn (1729-1786) acquired both Jewish and general educations and became an active participant in Berlin’s Enlightenment circles, while remaining a strictly observant Jew. He was also a major early proponent of the Haskalah, or Jewish Enlightenment. Throughout his career, he maintained a close friendship with the Gentile philosopher and playwright Gotthold Ephraim Lessing. Yuval Levin, noting the tremendous impact of this friendship on both thinkers, explains the connection between friendship and tolerance in Mendelssohn’s work:

Again and again, Mendelssohn found himself confronted by well-meaning Christians, even friends, who argued that he was simply too wise and sensible to remain a Jew, and pressing him to explain his resistance to their Christianity. He also gave thought to the related set of pressures on the Jewish world more generally in an era of self-confident enlightenment, which threatened to draw Jews away from their traditional communities.

Mendelssohn proposed a set of responses to these broader pressures that combined traditional practice and the confident assertion of the word of God as Jews understood it with a forthright case for toleration in the intellectual sphere. . . . [And] he denied the charge, leveled by some of those who sought his conversion, that the dictates of reason—the very Enlightenment ideals he championed—demanded that he abandon the faith of his fathers. . . .

But toleration, [in Mendelssohn’s view], did not amount to peaceful mutual disdain. It could be much more than that precisely because of friendship. Indeed, the idea of friendship was central to Mendelssohn’s response to the pressures he confronted. Friendship could help avoid turning disagreement into hostility. In making this argument, he flaunted his friendship with Lessing, publishing a kind of essay on friendship (formulated as a letter to Lessing) that offers an intense, idealized treatment of the possibilities of friendship as a source of both intellectual camaraderie and human meaning. It proposes the possibility of intellectual friendship overcoming differences of doctrine and belief without demeaning them, and so serving as a bridge in practice between conflicting and equally unpalatable alternatives that seemed unbridgeable in theory. And it is clearly a response, as well, to the pressures for conversion directed at Mendelssohn—pressures often offered in friendship, but which he implies risked running counter to the very idea of friendship. . . .

[Today], our society’s secular culture is constantly pressing in on those who espouse pre-liberal faiths. What it says—in its most inviting and least hostile forms—is basically that these believers are surely too wise and sensible to remain people of faith. Our progressive society thinks religious people should be able to reason their way to its own practices and beliefs, which it takes to be obvious rational truths, and morally superior, too. It sounds like some of what Mendelssohn heard from his friends.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.