As the only son of the great medieval Jewish philosopher Moses Maimonides, Abraham (1186-1237) followed in his father’s footsteps, serving as official head of Egypt’s Jewish community and its leading religious authority. In response to what he believed was a widespread spiritual crisis, he sought to reinvigorate Jewish piety by importing ideas and practice from Sufism, the mystical school of Islam then greatly influential in North Africa. This effort is the subject of a recent book by Elisha Russ-Fishbane. (Interview by Alan Brill.)

Historians of Jewish philosophy often consider it remarkable that the son of the great Maimonides—considered a champion of rationalism and moderation against mysticism and asceticism—would so blatantly stray from his father’s course and choose the mysticism of Sufism over the sober ideals of philosophy. The truth, as usual, is much more complicated.

Philosophy, in its medieval guise, was no less dedicated to personal liberation from physical attachments than was its Sufi counterpart. Mysticism, for its part, did not always entail a rejection of reason. In practical terms, Jewish philosophers and mystics of the medieval Islamic world advocated ways of life that were remarkably similar in orientation. . . .

Abraham . . . understood the path of [Sufi-influenced] pietism as the logical extension of the core principles of his father’s doctrine. That said, Abraham made far more extensive use of Sufism’s spiritual terminology than his father ever did, although there is [a scholarly] consensus that the father was not devoid of a modest Sufi vocabulary of his own. Even more meaningfully, Abraham embraced concrete Sufi practices within his own pietist circle and openly praised his Muslim counterparts, at times holding them up as a model for his own community.

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.