Spinoza probably lives in the memory of those who took an introduction to philosophy course as one of those strangely ambitious, God’s-eye-view metaphysicians who thought they could explain everything by logic and mathematics. There may also be some vague sense of a lens-grinding recluse, and a hint of a dubious relationship with his Jewish origins. All told, a tough subject for a biographer.

Rebecca Goldstein, a professor of philosophy and also a novelist, manages to write both a popular biography that explains Spinoza’s thought with considerable seriousness and a philosophic biography that is a remarkably good read. That her account becomes partly autobiographical is ultimately a strength of the book, since her experience with Spinoza stands in for that of many of her readers.

“Betraying Spinoza: The Renegade Jew Who Gave Us Modernity” (Schocken/Nextbook, 304 pages, $19.95) appears in a series on Jewish Encounters. But what, actually, is Jewish about Spinoza? Born “Baruch” Spinoza, a Dutch Jew of Portuguese Marrano extraction, he was excommunicated permanently by the Amsterdam community for denying the immortal soul and questioning the disclosed character of the Bible (i.e. inventing modern biblical criticism). He left cheerfully, changed his name to Benedict, and spent the rest of his life among liberal Protestants, developing a philosophy of universal reason that had no place whatsoever for allegiance to a religion or a people. The old question, always raised with figures like Marx or Freud, has its archetype in Spinoza: Aren’t they still, in some sense, Jewish? And it keeps coming back because it lies at the heart of the question of identity for many kinds of non-Orthodox Jews, from the occasional synagogue attendee to the ethnically conscious atheist.

Ms. Goldstein appropriately makes this question the central theme of her biography. Her title is witty. “Betraying” in her title means both disclosure and treachery. She is well aware that in connecting, often speculatively, Spinoza’s thought with his Jewish experiences and memory she is violating Spinoza’s own universalism, to which she is herself powerfully attracted.

Her story begins in an Orthodox women’s yeshiva, where the repulsive and condescending Mrs. Schoenfeld (damned for an unbecoming wig and ugly glasses and for disliking the author) states the Orthodox case against Spinoza, but somehow just manages to awaken sympathy for him in Ms. Goldstein’s youthful heart. Flash back to the tragic history of “La Nacao,” the “nation” of Portuguese Marranos who had made it safely to Amsterdam. There, zealous Calvinists, concerned at hearing chanting in a strange language behind closed doors, discovered to their relief that they had found Jews, not Catholics – and the discovered, in turn, were relieved that the Calvinists were relieved.

In addition to the perpetual Jewish problem of justifying God’s peculiarly cruel ways to his people, the Amsterdam community faced the particularly tormenting issue of what to think about the Marranos, Jews who had wanted to be Jews but, under compulsion, had converted and, for generations, maintained a private quasi-Judaism at the risk of their lives. The Marranos in Amsterdam could, presumably, be reconciled to true orthodoxy, but what about their relatives in Portugal and Spain? Would God save them because they were Jews or damn them because, whatever the mitigating circumstances, they were bad Jews? The Orthodox rationalists took the second view; the more messianic, influenced by Lurianic kabbalism, took the first. And then there was the horrific case of the Marrano Uriel Da Costa, who had, in a fateful anticipation of 19th-century German Reform Judaism, returned to preach a pure biblical Judaism cleansed of Talmudic excrescences and had been humiliated into a pathetic suicide.

Spinoza, Ms. Goldstein suggests, radicalized, rationalized, and secularized the universalist tendencies of the heterodox group and learned from Da Costa’s agonies to break all ties when trouble came. Thus, all of Spinoza’s powerful denials of particularity – his endeavor to overcome every being’s effort to be its particular self; his triumphant ascent to “The View From Nowhere” from which even one’s own death becomes a matter of indifference – are rooted in a very particular and painful, and above all Jewish, history.

There isn’t much personal evidence about Spinoza to go on, but the best piece Ms. Goldstein has is a letter he wrote to a former student, a Catholic convert, who wrote him a passionate and insulting letter calling on him to convert. Spinoza turns the tables; all the arguments the convert uses for Catholicism work even better for Judaism, including the testimony of martyrs, specifically a “certain Judah called the faithful” Spinoza knew of, who died singing a hymn at the stake. Of course, Spinoza isn’t defending Judaism; its folly is common ground for the argument. But it is striking that he, apparently unnecessarily, brings up that memory of Jewish fidelity and suffering.

Ms. Goldstein pleasantly conveys the rest of Spinoza’s not all that eventful life in the form of a fictional speculation whose climax his visit to the Jewish quarter near the end of his life. The most interesting (and documented) episode shows Spinoza’s landlord preventing him from putting up a protest sign at the scene of the murder of the (liberal) Witt brothers, thus contradicting all his own principles about caution and rational control of indignation.

Ms. Goldstein’s Spinoza, then, is in the end a familiar and consoling figure for enlightened Jews: not quite theirs but basically one of them. He permits them, like Ms. Goldstein herself, to become learned in philosophy and to see things beyond the grasp of Mrs. Schoenfeld, without entirely losing their Jewish identities. Much can be said for this, and Ms. Goldstein’s use of the Marranos, whose alienation from Judaism was mostly a matter of external compulsion, is a powerful case in point for the humane propriety of a broad definition of Yiddishkeit.

Yet what is the limit? Yes, the universal element in Judaism can be transformed into a post-Jewish, even anti-Jewish radical universalism that transcends its origins without entirely overcoming them. So, in some sense, even that vulgar Jew-hater Karl Marx could reasonably be credited with a “prophetic” or “messianic” passion for justice. And no doubt that could apply to some degree even to such descendants as Noam Chomsky or Norman Finkelstein. Should their Jewishness then be a cause for celebration? (Not by me.) The Orthodox had a better case than Ms. Goldstein allows Mrs. Schoenfeld to make, and Spinoza quite obviously knew it. In denying the existence of God in any other sense than “nature,” in attacking revelation, the crucial miracle, the one that guarantees all the others, Spinoza knew perfectly well what he was doing – and that it had to be intolerable to those who wanted to remain Jews.

That said, what is especially valuable about Ms. Goldstein’s Spinoza is what she brings to him as a teacher of philosophy. His “Ethics” surely has a claim to being the most formidably dry and abstract account of human life on offer, and yet it becomes clear from her account of teaching the text that Spinoza’s thought can inspire the most intense and passionate experiences of self-overcoming and moral change. Still, as a philosopher, Ms. Goldstein must know Nietzsche’s famous psychological suggestion about her hero.

Or consider the hocus-pocus of mathematical form with which Spinoza clad his philosophy … in mail and mask, to strike terror at the very outset into the heart of any assailant who should dare to glance at that invincible maiden and Pallas Athena: how much personal timidity and vulnerability this masquerade of a sick hermit betrays!

Ms. Goldstein’s own view, her own “betrayal” of Spinoza comes disconcertingly close to Nietzsche’s. It thus remains an open question if sufficient justice is done to Spinoza’s own claims when one grounds him, however kindly, on experiences he bet his philosophic reputation could be, and had been, overcome.

Mr. Baumann is the Harry M. Clor Professor of Political Science at Kenyon College.