Rabbi Aryeh Kaplan zt”l on his Yartzeit 14 Shevat 5743

by Rabbi Yair Hoffman

To this day, people marvel at his Chumash – a product of a mere nine months of researching and writing – an endeavor that would take others ten years or more to create – and one that would not match the quality of it. In the annals of modern Torah scholarship, few figures have left as indelible a mark in such a brief time as Rabbi Aryeh Kaplan zt”l. Described by those who knew him as “a meteor, a dazzling light that illuminated the darkened skies of post-Holocaust Torah learning, but burned out far too soon,” Rabbi Kaplan’s life was a testament to the transformative power of Torah and the boundless potential of the human spirit. In his mere forty-eight years, he produced approximately fifty books, inspired countless souls to return to their heritage, and opened doorways to realms of Jewish thought that had remained inaccessible to English readers for centuries.

From the Streets of the Bronx to the Halls of the Mir

Aryeh Moshe Eliyahu Kaplan was born Leonard Martin Kaplan on October 23, 1934, in the Bronx, New York City. His parents, Samuel and Fannie Kaplan, traced their Sephardic roots to the renowned Recanati family of Salonika, Greece—a city once known as the “Jerusalem of the Balkans.” For four centuries, Salonika had been home to the largest Sephardic Jewish community in the world, where Jews had flourished under Ottoman rule since the Spanish expulsion of 1492. But the upheavals of the early twentieth century—the collapse of the Ottoman Empire, the devastating fire of 1917 that left tens of thousands homeless, and the rise of Greek nationalism—had driven many Salonikan Jews to seek new lives in America. The Kaplan family’s ancestors had originally fled Spain for Salonika during the Inquisition; now, generations later, they found themselves in a new world.

The Bronx of the 1930s was a world unto itself—home to one of the largest Jewish communities in the United States. At its peak in 1930, nearly fifty percent of the borough was Jewish, with over 360,000 Jews residing in the South Bronx alone. It was the era of the “front-stoop Bronx,” where neighbors sat outside on summer evenings, children played stickball in the streets, and families promenaded along the Grand Concourse—the borough’s own Champs-Élysées—stopping for sodas at Krum’s or gathering outside the hundreds of synagogues that dotted the neighborhood. Yet the Kaplan family, like many Sephardic immigrants, maintained only a minimal connection to Jewish observance.

Tragedy struck early. On December 31, 1947, when Leonard was just thirteen years old, his mother passed away. His two younger sisters, Sandra and Barbara, were sent to a foster home. Leonard, expelled from public school after acting out, found himself adrift—a street kid in the rough neighborhoods of the East Bronx, at a time when the borough was beginning to show the first signs of the decline that would accelerate in the coming decades.

Yet Hashem’s providence works in mysterious ways. Leonard was encouraged to say Kaddish for his mother by Klausenberg Chassidim, and on his very first day at the minyan, a fourteen-year-old Klausenburger chassid named Henoch Rosenberg noticed him standing lost and confused—without tefillin, unable to follow the siddur. Henoch befriended him immediately. Together with his siblings, Henoch taught Leonard Hebrew, and within days, the young orphan was learning Chumash on his own. The seeds of Torah had found fertile ground.

At fifteen, Leonard enrolled in Yeshiva Torah Vodaas in the Williamsburg section of Brooklyn, where he flourished despite his late start. His brilliance quickly became apparent. At just eighteen, he was selected to join a select group of talmidim—including future luminaries like Rabbi Mendel Weinbach and Rabbi Nisson Wolpin—sent across the country to Los Angeles to help Rabbi Simcha Wasserman establish Yeshiva Ohr Elchonon. Despite being much younger than his peers, young Aryeh Kaplan was deemed worthy of this mission.

In 1956, he traveled across the Atlantic to Eretz Yisroel to learn at the Mir Yeshiva in Yerushalayim. There, in the holy city still recovering from the 1948 War of Independence and divided by walls and barbed wire, he received Yoreh Yoreh and Yadin Yadin semicha from the legendary Rosh Yeshiva, Rav Eliezer Yehuda Finkel zt”l, as well as from Chief Rabbi Yitzchak HaLevi Herzog zt”l. His ordination certificate described him as “well-known as a genius, an expert in Shas, Rishonim, Acharonim.” The street kid from the Bronx had become a talmid chacham of the highest caliber.

The Scientist and the Torah Scholar

What made Rabbi Kaplan truly extraordinary was his rare combination of Torah mastery and scientific brilliance. After returning from Eretz Yisroel, he pursued secular studies at the University of Louisville in Kentucky, earning his bachelor’s degree in physics with high honors in 1961. Louisville, situated on the banks of the Ohio River, was home to a small but established Jewish community of some 12,000 souls—a far cry from the bustling Jewish neighborhoods of New York. While there, he taught at Eliahu Academy, the city’s Jewish day school, and immersed himself in both worlds of study.

He then went on to complete a master’s degree in physics at the University of Maryland in College Park. As a graduate student, he was listed in “Who’s Who in Physics” as one of the most promising young physicists in America. He even worked briefly at the National Bureau of Standards as a research scientist, specializing in magneto-hydrodynamics.

It was in Louisville that he met Tobie Goldstein, who hailed from the small town of Marigold, Mississippi—deep in the Mississippi Delta, where a handful of Jewish families had maintained their heritage amid the cotton fields of the rural South. They married in 1961 and would eventually be blessed with nine children—three daughters and six sons.  

His wife was the strength behind him who encouraged him to reach ever higher in ruchniyus.  He succeeded enormously. And the world is much richer for it. 

Rabbi Kaplan worked briefly as a research scientist, but the pull of spiritual service proved irresistible. In 1965, when asked why he abandoned a promising physics career for the rabbinate, he answered simply: “Hashem had a mission for me.”

His early rabbinic career took him to small Jewish communities across America’s heartland—places far removed from the great Torah centers of the East Coast. He served congregations in Mason City, Iowa; in the Smoky Mountain region of Tennessee, serving the tri-cities of Bristol, Johnson City, and Kingsport; and in communities in New Jersey and upstate New York. These were the years when American Jewry was in flux, when many small-town Jewish communities were beginning to decline even as suburban Jewish life was flourishing elsewhere.

A Physicist’s Approach to Torah

Rabbi Kaplan’s scientific training became the hallmark of his literary approach. “I use my physics background to analyze and systematize data,” he once explained, “very much as a physicist would deal with physical reality.” This methodology enabled him to undertake monumental projects and produce works of remarkable clarity and precision.

His writing was extraordinary in its seamless incorporation of ideas from across the spectrum of rabbinic literature—Talmud, halacha, Kabbalah, and Chassidus—while never ignoring scientific insights. As Rabbi Pinchas Stolper observed, “He saw harmony between science and Judaism, where many others saw otherwise. He put forward creative and original ideas and hypotheses, all the time anchoring them in classical works of rabbinic literature.”

He made the maps for his Chumash with a lightbox that he himself constructed.  This was all before the internet. “He found different backgrounds to make the oceans,” his son recalls.

His daughter Abbie was sixteen when he passed away. “He was always learning or typing. He did all his writing, fifty books or so, in ten years.”

His son Micha explains that he was a hundred percent lishma – not about money, not about kavod.  He learned in Torah V’Daas and saw Rav Pam zatzal act in the same way – one hundred percent lishma.

The Living Torah: His Magnum Opus

Perhaps Rabbi Kaplan’s best-known work is “The Living Torah,” his groundbreaking translation of the Chumash completed in 1981. Rabbi Kaplan affectionately called it his “tenth child,” because it took him exactly nine months to complete.

The Living Torah was revolutionary in its approach. It was one of the first translations structured around the parshiyos, and it skillfully balanced the basic peshat meaning with traditional rabbinic interpretation. The work features detailed indices, thorough cross-references, extensive footnotes with maps and diagrams, and meticulous research on realia, flora, fauna, and geography—drawing on sources as diverse as Josephus, Dio Cassius, Philostratus, and Herodotus.

Rav Chaim Pinchas Scheinberg zt”l reportedly said that the translation is so precise that if one cannot read the Targum Onkelos, one can fulfill the requirement of Shnayim Mikra V’Echad Targum using The Living Torah. It remains a staple in Jewish homes and shuls worldwide, having been reissued in a Hebrew-English edition with haftaros for synagogue use.

He also wanted to do so more.  His son, Micha, relates that he wanted to make a Living Torah for children.  

Opening the Gates of Kabbalah and Jewish Meditation

The 1960s and 1970s witnessed a remarkable phenomenon in American culture: thousands of young Jews, alienated from what they perceived as the sterile conformity of suburban synagogue life, were drawn to Eastern religions and meditation practices. From the ashrams of India to the Zen centers of California, Jewish seekers were looking everywhere except within their own tradition for spiritual depth. Rabbi Kaplan recognized the urgent need to reveal Judaism’s own rich meditative tradition.

His translations and commentaries on classic works of Jewish mysticism—including the Sefer Yetzirah, the Bahir, and Ramchal’s Derech Hashem—opened doorways that had remained sealed to English readers for centuries. These ancient texts, some dating back to Talmudic times, had been the province of only the most advanced scholars. Rabbi Kaplan made them accessible to a generation hungry for spiritual authenticity.

His books “Meditation and Kabbalah” and “Jewish Meditation: A Practical Guide” demonstrated that authentic Jewish meditative practices existed and had been an integral part of mainstream Judaism until the eighteenth century. Through simple exercises and clear explanations, Rabbi Kaplan provided tools for developing spiritual potential through authentically Jewish meditative practice.

In his translation of Sefer Yetzirah, Rabbi Kaplan brought the text’s theoretical, meditative, and mystical implications to light. He explored the dynamics of the spiritual domain, the worlds of the sefiros, souls, and angels—making accessible what had been the province of only the most advanced scholars.

Champion of Breslov and Savior of Rebbe Nachman’s Kever

Rabbi Kaplan’s connection to Breslov Chassidus came through Rabbi Zvi Aryeh Rosenfeld zt”l, the pioneer who single-handedly introduced the teachings of Rebbe Nachman to American shores. Beginning in 1973, Rabbi Kaplan produced the first-ever English translations of seminal Breslov works, including “Rebbe Nachman’s Wisdom” (Sichot HaRan), “Until the Mashiach: The Life of Rabbi Nachman,” and “Rabbi Nachman’s Tikkun” (based on the Tikkun HaKlali).

In 1979, Rabbi Kaplan played a pivotal role in one of the most dramatic episodes in modern Jewish history. The Soviet government, then in the twilight years of the Brezhnev era, was planning to demolish the old Jewish cemetery in Uman, Ukraine—including the kever of Rebbe Nachman of Breslov—to build high-rise apartment buildings. Uman, a city in central Ukraine between Kiev and Odessa, had been the site of one of the most horrific massacres in Jewish history in 1768, when an estimated 30,000 Jews were murdered by Cossacks and Haidamaks. Rebbe Nachman had specifically requested to be buried there, among the holy martyrs.

Word of the impending demolition reached the Breslov community through Mrs. Zubeida, a local Ukrainian woman who lived near the gravesite. Reb Michel Dorfman, the legendary chassid who had kept the flame alive through decades of Stalinist oppression and had spent six and a half years in Siberian labor camps for the crime of Jewish observance, traveled urgently to America.

When Reb Michel and Rabbi Noson Maimon approached Rabbi Kaplan for help, his response was characteristic. “Ha, ha, Reb Michel,” he laughed, “do you think Rabbi Nachman only belongs to Meah Shearim? Martin Buber and Elie Wiesel wrote about him. There isn’t a university in the United States that doesn’t study the chassidic movement!” Using a manual typewriter, Rabbi Kaplan sat down and composed a masterful presentation on the spot, complete with maps of Ukraine showing exact coordinates.

The letter was forwarded to President Jimmy Carter through Rabbi Pinchas Teitz and White House Counsel Robert Lipshutz. Just days later, at the SALT II summit in Vienna—where Carter and Brezhnev were negotiating nuclear arms limitations—the American president raised the matter of a chassidic rebbe’s grave. The result was a secret agreement: the Kremlin would proceed with construction throughout the area, but Bilensky Street—where Rebbe Nachman’s grave stood—would remain untouched. Today, tens of thousands of Jews travel to Uman annually for Rosh Hashanah, a pilgrimage made possible in part by Rabbi Kaplan’s quick thinking and clear prose.

The Heart of NCSY and the Teshuvah Movement

In 1972, the Kaplan family—now with three children and eventually to have nine—settled in a house in the heart of Boro Park, Brooklyn, on 48th Street and 16th Avenue. Later they moved to the Kensington neighborhood. It was here that Rabbi Kaplan was “discovered” by Rabbi Pinchas Stolper z”l, the legendary founder of NCSY.

This author was close with Rabbi Stopler and studied Rav Hutner’s Pachad Yitzchok with him.  Rabbi Stolper lived and breathed “kiruv” and was a close talmid of Rav Hutner zt”l who put him on this path. Rav Aharon Schechter z”l followed this path as well.

Rabbi Stolper had spotted an article on “Immortality in the Soul” in Intercom, the journal of the Association of Orthodox Jewish Scientists, and was immediately struck by Rabbi Kaplan’s “unusual ability to explain a difficult topic—one usually reserved for advanced scholars, a topic almost untouched previously in English—with such simplicity that it could be understood by any intelligent reader.”

When Rabbi Stolper invited him to write on the concept of tefillin for NCSY, Rabbi Kaplan completed the 96-page manuscript of “God, Man and Tefillin”—with sources and footnotes from Talmud, Midrash, and Zohar—in less than two weeks. The book was masterful, comprehensive, inspiring, yet simple—a pattern that would characterize all his succeeding works.

The timing was providential. The late 1960s and 1970s were years of social upheaval in America—the counterculture, Vietnam, Watergate. Many Jewish teenagers, caught between the conformist expectations of their parents’ generation and the rebellious spirit of the times, were searching for meaning. NCSY, with Rabbi Kaplan as its intellectual engine, offered them authentic Torah wisdom in accessible, contemporary language.

Rabbi Kaplan wrote ten highly influential books for NCSY, addressing foundational principles of Jewish faith through such works as “Love Means Reaching Out,” “The Fundamentals of Jewish Faith,” “Jerusalem: Eye of the Universe,” “Sabbath: Day of Eternity,” “Waters of Eden: The Mystery of the Mikvah,” and “Tzitzith: A Thread of Light.” These works remain as relevant today as they were in the 1970s.

At NCSY conventions, Rabbi Kaplan was legendary. One former NCSYer recalled a friendly, unassuming man who patiently answered questions and discussed anything on your mind—from the simplest to the most complex issues. This “super-advisor” became a valuable friend to countless teenagers. At one convention, she excitedly told him that she was looking forward to hearing the famous Rabbi Aryeh Kaplan speak—not realizing she had been talking to him all along.

“Aryeh Kaplan was the last adult standing” at drawn-out NCSY banquets, colleagues recalled. Rabbi Baruch Taub, NCSY’s associate national director, remembered watching him interact with teens: “It was something very special, because he related to every one of them, patiently answering each one’s questions. And all without a trace of ego, never letting on as to what he really was. He was both an incredible talmid chacham… and was a physicist, too, yet his whole persona bespoke humility.”

The Man Behind the Books

Those who knew Rabbi Kaplan personally speak of a warmth and simchas hachaim that permeated his being. Naftali Miller, now Agudath Israel of America’s national director of development, was a neighbor of the Kaplans in Kensington. As a frequent childhood visitor to their home, he vividly recalls coming in one Friday night: “Rabbi Kaplan took my hand to dance with me as he sang, ‘We want an elephant from the Bronx Zoo!’ It was just one of these nonsensical songs he would make up and sing to make things geshmak and upbeat in the house.”

“And then there’s one thing I don’t remember,” Miller added. “I can’t recall ever seeing him get upset at anything.” As a child, he would watch Rabbi Kaplan sit in shul “as if he were just a simple Jew, just another one of the mispallelim, when in truth he was the neighborhood’s most brilliant resident, its crowning glory.”

Rabbi Elkins, another close associate, recalled the Shabbos table in the Kaplan home, which attracted “a fascinating variety of people—bnei Torah and new baalei teshuvah, students, a professor of mathematics or physics, a prominent psychologist. They all felt comfortable because Rabbi Kaplan spoke their language and was completely conversant in their fields of interest.”

His home was always open to visitors, great and humble, from every segment of the Jewish community. His Shabbos table was always crowded with guests attracted to the beauty of Torah life that he lived and to the endless stream of wisdom and Torah insight that flowed from his lips. He labored tirelessly, day and night, producing more outstanding works of Torah scholarship single-handedly than teams of other authors working in the field. Yet he somehow managed to find time for the simplest Jew, perfect strangers seeking answers to the spiritual questions in their lives.

A Monumental Literary Legacy

In addition to his better-known works, Rabbi Kaplan produced “The Handbook of Jewish Thought,” which he called “the most important thing I’ve ever done.” This two-volume Torah encyclopedia systematically formulated Jewish belief, distilling the diverse approaches of classic works of machshavah, Kabbalah, and philosophy into a comprehensive whole.

From 1976 onward, Rabbi Kaplan’s major activity was translating the Me’am Lo’ez Torah Anthology into English. This monumental work had been composed in Ladino—the Judeo-Spanish language of the Sephardic world—and was the most beloved Torah commentary in communities from Salonika to Constantinople to the Sephardic diaspora of the Americas. Colleagues described him working with his typewriter, “the Me’am Lo’ez in Ladino on one side of him and the Hebrew version on the other side, and he’d look from one to the other and back again, comparing and contrasting and typing away furiously the entire time.” For the descendant of Salonikan Jews, this project must have held special meaning—a bridge to his own ancestral heritage.

By the time of his passing, Rabbi Kaplan had produced a total of close to fifty original works. Beyond their sheer volume, it is the diverse scope of his body of work that astounds: translations of the Ramchal, kabbalistic texts, Breslov classics, the Torah Anthology, and original works on meditation, mysticism, and Jewish philosophy. His works have been translated into Czech, French, Hungarian, Modern Hebrew, Portuguese, Russian, German, and Spanish, continuing to bring light to Jews worldwide.

A Flame That Still Burns

On Friday, January 28, 1983—14 Shevat 5743—Rabbi Aryeh Kaplan suffered a sudden, massive heart attack at his home in Brooklyn. He was just forty-eight years old. His funeral was held at Shomrei Hadas chapel in Brooklyn, and he was buried on Har HaZeisim in Yerushalayim—the Mount of Olives, overlooking the holy city where he had once received semicha as a young man.  His son Micha was 12 and 1/2 years old when his father had finished his Bar Mitzvah pshetl on a Thursday night.  The next day he passed away.  

The Jewish world mourned the loss of this towering figure who had burned so brightly and been extinguished so soon. He left behind his devoted wife Tobie and nine children, as well as countless students and readers whose lives he had transformed.

“Throughout history, Jews have always been observant,” Rabbi Kaplan once remarked. “The teshuvah movement is just a normalization. The Jewish people are sort of getting their act together. We’re just doing what we’re supposed to do.” Few did more to facilitate that “normalization” than Rabbi Aryeh Kaplan.

In 2021, NCSY republished Rabbi Kaplan’s works as “The NCSY Rabbi Aryeh Kaplan Library,” introducing his illuminating writings to a new generation. The Aryeh Kaplan Academy day school in Louisville, Kentucky—where he once taught and where he met his wife—is named in his honor, a fitting tribute in the heartland city that played such a pivotal role in his life.

Rabbi David Bashevkin, NCSY’s director of education, has noted that Rabbi Kaplan’s own life story demonstrates “that anyone, no matter how humble his or her Jewish background, can become learned.” The street kid from the Bronx who discovered Torah at thirteen went on to open the gates of Jewish wisdom to millions. His works continue to accompany baalei teshuvah through the maze of Jewish learning, providing clear, succinct, yet sophisticated explanations and answers.

Rabbi Kaplan once quoted a poem by Elizabeth Barrett Browning: “Earth is crammed with heaven / And every common bush is afire with G-d / But only he who sees takes off his shoes.” In many ways, this captures who Rabbi Aryeh Kaplan was and what he intended to demonstrate. There is holiness to be found wherever you look—and Rabbi Kaplan spent his life helping others to see it.

His legacy is four-fold:  His Seforim, the people he was mekarev, his remarkable family of Bnei Torah, and now his grandson, Rabbi Zalman Rosenfeld, has opened a Yeshiva in Flatbush called, “Gevuras Yisroel” named after Rabbi Yisroel Plutchak zt”l.