Saturday, April 4, marks the 316th anniversary of the passing of a seminal figure in the history of American Jewry. And while Rabbi Isaac Aboab da Fonseca's name may not sound familiar to many contemporary North and South American Jews, the heroic example he set of fighting for religious liberty while simultaneously defending the integrity of Judaism remains compellingly relevant. Indeed, as much of Diaspora Jewry struggles to walk the fine line between fidelity to tradition and openness to modernity, it is worth recalling the tenacity and resolve of this very special personality. Da Fonseca was born in 1605 in the town of Castro d'Aire in Portugal to a family of Anousim (whom historians refer to by the derogatory term Marranos). His ancestors had been Jews who were forcibly converted to Catholicism yet continued to practice Judaism in secret, risking the ire of the Inquisition and its henchmen. As the Church intensified its efforts to hunt down and persecute crypto-Jews, da Fonseca's family decided to flee Portugal. After a brief stay in France, they made their way to Amsterdam, where the young boy and his loved ones openly returned to Judaism. Da Fonseca proved to be a prodigy, and by the age of 21 was appointed to serve as the hacham, or spiritual leader, of one of Amsterdam's three synagogues. But it was some 15 years later, in 1642, that he took the fateful, and somewhat perilous, decision to accept the post of rabbi in a community on the other side of the Atlantic Ocean. THE PORT CITY of Recife, in northeastern Brazil's Pernambuco state, had recently been captured from Portuguese colonizers by the Dutch. The town's 600 Jews, most of whom were Sephardim of Portuguese origin, invited Da Fonseca to serve as leader of their community. Bravely choosing to leave behind his highly regarded position in Holland for the uncertainties of life in the New World, da Fonseca made the voyage and assumed the post of hacham of the Kahal Zur Israel synagogue. He thus became the first appointed rabbi of the Americas. The community thrived under his leadership, but just four years later, the Portuguese army attacked Recife in an effort to recapture the city. It offered the Jews protection if they agreed not to take part in the fighting, but da Fonseca and the community would hear none of it. Acutely aware of Portugal's intolerance toward the Jews, which contrasted sharply with the relative freedom they enjoyed under Dutch rule, Recife's rabbi and his flock chose to play an active part in the city's defense, courageously siding with the cause of religious liberty. For most of the next decade, while the Portuguese besieged Recife, the Jews took part in the fierce fighting, and da Fonseca led public prayers on behalf of the resistance. In a Hebrew poem that he later penned, the rabbi wrote that "many of the Jewish immigrants were killed by the enemy; many died of starvation. Those who were accustomed to delicacies were glad to be able to satisfy their hunger with dry bread; soon they could not obtain even this. They were in want of everything and were preserved alive as if by a miracle." According to the American Jewish Historical Society, it is the oldest known Hebrew text written in America. FINALLY, IN 1654, the Dutch surrendered, and the Jews were forced to leave Brazil. The rabbi and most of his congregants headed back to Holland, but a boat carrying 24 of them was blown off course and ended up in New Amsterdam (later New York), making them the first Jews to settle in North America. Back in Amsterdam, da Fonseca resumed his post as hacham, and was appointed to serve on the city's Beit Din (rabbinical court). It was there, shortly afterward, that he took part in the sharp controversy surrounding philosopher Baruch Spinoza. After Spinoza had provoked widespread anger in the Jewish community over his views on various subjects such as the eternity of the soul and the nature of God's existence, a writ of excommunication against him was read out publicly on July 24, 1656, from the pulpit of Amsterdam's Talmud Torah synagogue. Among those who consented to the ban on Spinoza was da Fonseca. Modern philosophers, of course, consider Spinoza as something of a hero, hailing him as one of the people who laid the foundations for rationalism, the Enlightenment and biblical criticism. Naturally, they view his excommunication with derision and contempt. How, then, are we to reconcile da Fonseca's participation in the ban, particularly in light of his previously forthright stance on behalf of religious freedom? The answer, I think, is really quite simple, and can be summed up in a single word, one which carries within it the secret to Jewish survival in the Diaspora: boundaries. When it came to preserving a level playing field for all religions in an open society, da Fonseca was a forceful advocate. He understood that freedom to practice one's faith was in everyone's collective interest, including of course the Jews. But when Judaism and its fundamental beliefs came under attack from within, he was no less vigorous in manning the barricades and defending the faith. Because he knew just as well that without a firm anchor, Jews could easily sail off course and assimilate. In other words, open boundaries are key as a basic ground rule for society, but strict boundaries are essential to preserving a faith community. You simply cannot have it any other way. So as important as it may be nowadays to fight for civil rights in the public sphere, it is no less crucial to strengthen the ramparts that keep us Jewish. Centuries later, it is a lesson that the Jews of America would do well to learn from their first spiritual leader, Rabbi Isaac Aboab da Fonseca. May his memory be for a blessing.