"Uriel da Costa

 had been baptized Gabriel, born in Oporto, Portugal. His father was a devout Catholic, but his mother came from a converso family and, as the work of recent historians has unearthed, most likely observed some of the secret rites of Marranism. Gabriel studied canon law at the University of Coimbra and was a church treasurer. Da Costa described himself as having become disillusioned with Christianity. In studying and comparing the New Testament with the Five Books of Moses, he found contradictions and reached the conclusion that Judaism, from which Christianity had sprung, presented the authentic experience, with Christianity a corruption of it. He also confessed that Christianity’s emphasis on hell’s damnation terrified him. Soon both he and his five brothers were inwardly identifying themselves as Jewish. After the death of their Catholic father, the six boys, together with their mother, Banca, determined to leave Portugal.

He presents himself as having voluntarily left Portugal for the freedom to practice Judaism openly, but the historian Israel Révah, researching the records of the Oporto Inquisition, found that, unsurprisingly, the converso had attracted the attention of the office of the Inquisition, which was preparing a devastating case against him, so his emigration was most likely not simply a spiritual journey but an attempt to escape with his life.

Once in Amsterdam, da Costa found that the Judaism being practiced there did not live up to his expectations. The departures from the pristine ancient religion of Moses were, in his eyes, unjustifiable extensions of God’s direct revelations. The accretions of rabbinical ordinances and Talmudic rulings, the codification of the so-called Oral Law, offended da Costa’s construction of what Judaism ought to be. The organized hierarchical religion of the rabbis was as much a corruption of the original Mosaic Code as was Catholicism, and da Costa set about single-handedly to reform it, to purify it of all its post-Mosaic content. As the historian Yirmiyahu Yovel points out, we must read Examplar with several grains of salt. It is highly dubious that da Costa believed that “the religion of Moses had been petrified for over two millennia, waiting for Uriel da Costa to perform an unhistorical leap into it. However vaguely and unwillingly, da Costa was aware that post-biblical Judaism was different from the original model. But he hoped and believed that the fluid New Jewish situation offered a historical opportunity to remedy this. … Da Costa expected that (unlike the Catholicism of which he had despaired) Judaism could lend itself to a purifying reform in the original direction of the Bible, especially within the New Jewish communities where, out of a minimal and shattered basis, former Marranos were trying to reconstruct a Jewish life for themselves. Since these New Jews were already engaged in an effort to recapture their lost essence, they may as well have regressed further back to their origins and restored the purer biblical Judaism that elsewhere had been obliterated.”

Needless to say, his efforts did not find favor with the rabbis of Amsterdam, who were charged with the task of transporting the former Marranos back to the halakhic Judaism from which history had separated them.

Da Costa reacted with fury to the intransigence of the religious authorities of the community, and in search of a more authentic Judaism left Amsterdam for the Sephardic community of Hamburg, which did not respond any more favorably to his reforming ideas than Amsterdam had. In 1616 he composed a set of eleven theses attacking what he called “the vanity and invalidity of the traditions and ordinances of the Pharisees.” He claimed that the rabbis, in equating Talmudic interpretations with the Torah, “make the word of man equal to that of God.”

On August 14, 1618, da Costa was put in kherem by the chief rabbi of Venice, Rabbi Leon de Medina, who was the teacher of the chief rabbi of Amsterdam, Rabbi Morteira. He was also put under a ban in Hamburg, and returned to Amsterdam, still fighting. He committed his protest to writing, publishing in 1624 his feisty Exame das tradições phariseas (Examination of the Pharisaic Traditions), which objects to such laws as male circumcision, the laying on of tefillin, or phylacteries, and also vehemently protests the extrabiblical inclusion of the doctrine of immortality and divine retribution. This doctrine, he confesses, was precisely what had driven him from Catholicism. “In truth, the most distressful and wretched time in my life was when I believed that eternal bliss or misery awaited man and that according to his works he would earn that bliss or that misery.” He was terrified by the eschatological metaphysics and found peace only when he realized the absurdity of the claim that the soul might survive the death of the body, since the soul is only an aspect of the body, the vital source that animates it and also accounts for rationality.

(...)

But the community was under rabbinical orders to regard the religious renegade as a pariah. Da Costa writes in the Examplar that even children mocked him on the streets and threw stones at his windows. Nevertheless, da Costa did not absent himself from the community. Of course, he was already under kherem in Venice and Hamburg, and he must have reasoned that wherever he went Jewish communities would find him intolerable. But interestingly, even though he had reached the intellectual conclusion that Judaism, like Christianity, was but a man-made system arising out of man’s needs, and that the true religion was deism—the belief, based solely on reason and not revelation, in a God who created the universe and then left it to its own devices, assuming no control over life and never intervening in the course of history or of natural phenomena—still, on an emotional level, da Costa seemed incapable of taking leave of Judaism, or at least of the Jewish community. He lived among the Amsterdam Sephardim as a despised individual, clinging to the margins of a world that had become for him an open narcissistic wound. Yet he did not simply pick himself up and quit Jewish life decisively. Though the Jews had excommunicated him he was not prepared to excommunicate the Jews. His disinclination to think of himself as outside the religious community is telling and casts a dramatic contrast with Spinoza. "

   Rebecca Goldstein, Betraying Spinoza:The Renegade Jew Who Gave Us Modernity, p.133-137.