In his influential Historical and Critical Dictionary, the 17th-century French philosopher Pierre Bayle wrote that an unnamed Jew stabbed Benedict Spinoza—and that this apparent attempt on his life precipitated his break with the Amsterdam Jewish community. The story is given some credibility in an early biography of the Jewish apostate thinker, published in 1705, even if some of the details differ in the two accounts. But, unlike previous biographers of Spinoza, Steven Nadler believes that, if the stabbing happened at all, it was provoked not by the philosopher’s heretical beliefs but by the anger of a debtor from whom Spinoza had attempted to collect:

The Amsterdam Portuguese Jewish community [to which Spinoza then belonged] was fairly cosmopolitan. To be sure, one was not free to proclaim whatever one wanted; . . . there were clear limits not just to what one could do but also to the ideas one could voice. But many members of the community, including its rabbis, engaged in wide-ranging philosophical and theological discussions. Even if Spinoza went too far—and he clearly did—to see the attempted murder as a reaction to his heretical views and rejection of communal authority now seems to me a little far-fetched. In fact, there is a more readily available and plausible, if mundane, explanation. . . .

When Spinoza’s father Miguel died in 1654, Spinoza and his brother Gabriel took over the family importing firm. Several notary records from April and May 1655 provide an interesting glimpse into Spinoza’s character and business acumen. There were three Portuguese Jewish brothers, Anthonij, Gabriel, and Isaac Alvares, who . . . were jewel dealers and apparently rather shady characters. Spinoza had a bill of exchange—basically an IOU—for the amount of 500 guilders to be paid by Anthonij Alvares. . . .

There was certainly bad blood between Spinoza and the Alvares brothers, who appear to have had a tendency to physical violence. Not only were they giving Spinoza the runaround [when he tried to collect the debt], but they would have been angered by his resort to the legal authorities to have them arrested. It is a classic tale, from a competitive mercantile city in the Dutch golden age where trade disputes were frequent and where it was essential to one’s business to maintain a good reputation for fair dealing. With notarized complaints and arrests, Spinoza publicly put the Alvares brothers under suspicion of being untrustworthy. It would not be surprising if one member of this . . . trio responded with an attack on Spinoza’s life.

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.