Sunday 4 December 2022

408) Rebbe Professor Isadore Twersky


The two faces of  Rabbi Professor Twersky


This article, based extensively but not exclusively on the research by Rabbi Dr Carmi Horowitz,[1] looks at the extraordinary story of Rabbi Professor Isadore (Yitzchak) Twersky (1930-1997). As both a rebbe and professor, Isadore Twersky straddled two very distinct worlds.

The story

Rebbe Professor Twersky, as he was affectionately known, was born into a Chassidic line of rebbes from the Chernobyl dynasty. He was a great-grandson of Rabbi David of Talne, an important leader of the Chassidic movement in Ukraine during the nineteenth century. By all expectations, he should have just grown up to become another rebbe in the chain going back to R. Nachum of Chernobyl (1730-1789), a student of the Baal Shem Tov. The Talner Chassidim are a branch of the Chernobyl Chassidic dynasty.

So many details of R. Twersky’s life do not fit the typical profile of a child growing up in a Chassidic rebbe’s home. The young Isadore did not study at a yeshiva but was taught privately by melamdim (religious teachers) who came to his home in the early mornings and evenings. Instead, he attended a public elementary school and then Boston Latin School, the prestigious and oldest school in America. The ethos of this school was modeled on the ancient Greek view elevating the humanities and pursuits of the intellect and soul:

"From its beginning, Boston Latin School has taught its scholars dissent with responsibility and has persistently encouraged such dissent" (from the school's homepage).

After completing his schooling, he attended a Zionist and Hebraist Hebrew Teachers College and then became a student at Harvard University.

He studied under Professor Harry Austryn Wolfson, the first to open a Judaic Studies centre at a university in the United States and of whom it was said that he fulfilled the goal of the nineteenth-century Wissenschaft des Judentums of the Enlightenment movement.

R. Twersky was later to write of his Professor Wolfson:

“He was reminiscent of an old-fashioned gaon, transposed into a modern university setting, studying day and night” (Twersky 1975).[2] 

Wolfson wrote on Philo, Maimonides, as well as the Church Fathers, and R. Twersky points out that he collapsed the barriers between Christian, Islamic and Jewish philosophies (Twersky 1975). R. Twersky refers to his teacher as a “daring” scholar.

In 1949 R. Twersky took a year off from Harvard to study at the Hebrew University under Yitzchak Baer, Ben-Zion Dinur and Gershom Scholem. While in Isreal he continued to combine his secular and religious life by associating with his cousin the Rachmastrivker Rebbe, as well as the Israeli author S. Y. Agnon.

On his return to Harvard, R. Twersky wrote a thesis on medieval Christian historiography and then completed his doctoral dissertation on Raavad, a twelfth-century critic of Maimonides.

While still a PhD student, he married Atarah, the daughter of Rabbi Joseph B. Soloveitchik, known as the Rav. He developed a close relationship with his father-in-law, and the two studied Talmud together for the next thirty years. R. Soloveitchik was also a great secular scholar mastering Western philosophy, from its early Greek origins until the twentieth century.

On completion of his doctorate in 1956, R. Twersky was appointed as a lecturer at Harvard and in 1965 he took over from Professor Wolfson when the latter retired.

“For the next thirty-two years, Harvard University became a unique center for the study and research of Jewish intellectual history. Students of a high caliber who came with a substantial knowledge of Jewish studies were attracted to Harvard, and many of them subsequently produced important pieces of scholarship that carried the stamp of their teacher’s scholarly methodology” (Horowitz 2015:253).

R. Twersky wanted benei Torah (educated religious students) to study academia and he encouraged students to reconsider the relationship between universities and yeshivot. He wrote:

“Scientific tools cannot replace fundamental knowledge of Judaism; philosophic and pseudo-philosophic views cannot cover up ignorance” (Twersky 1970:32).[3]

Amongst his many students, he had about forty graduates who went on to have scholarly careers. R. Twersky was not only interested in promoting Jewish studies but in advancing the standards of academic excellence at Harvard University in general. To that end, he had close contact with the university leadership and its deans and twice served as chairman of the Department of Near Eastern Languages and Civilizations.

While all this academic activity was going on, he was deeply involved in his father’s Chassidic court, the Talner Beit Midrash and in 1982, he succeeded his father and became the next Talner Rebbe. Yet he still held firm to his rationalist approach to Judaism: 

“His own vision of Judaism drew on Maimonides’ notion that philosophy is an integral part of the mitzva of talmud Torah. He firmly adhered to Maimonides’ maxim, ‘One should accept the truth from whatever source it proceeds’[4]” (Horowitz 2015:256).

R. Twersky was in the process of trying to establish guidelines for a shift in the approach to Torah education by introducing: 

“various halakhic perspectives on the study of such areas as the natural sciences, arts and literature, history, and physical education – including the question of their relative priority…”[5] 

But, unfortunately, he passed away before the project could bear fruit. 

In harmony or in tension

Considering the vastly different worlds in which R. Twersky was operating, the question begs as to whether he was able to live in harmony with these influences or whether he lived within the tensions generated by them. Horowitz attempts to resolve this issue by sharing his observations of R. Twersky from when he was his student at Harvard. 

Horowitz informs us that R. Twersky made a point of not missing praying with a minyan three times a day. He would regularly recite the Tehillim (Psalms) and he followed Chassidic customs meticulously. His prayer was not ostentatious but reflected a quiet sense of deep concentration. He performed many acts of kindness and his respect for his parents was unlimited. His Talmud shiurim (lessons) in the Talner Beit Midrash were traditional, and he adopted much of the methodology of his father-in-law, R. Soloveitchik. His divrei Torah (short Torah lessons) were not cold and academic but referenced the moral and inward nature of religious life, although his academic analysis of Maimonides was a common motif in these talks. Horowitz shares a personal interaction he had with R. Twersky: 

“Once, during my first or second year at Harvard, I asked him, at the urging of one my friends, ‘Does not the study of Jewish history border on bitul Torah (i.e., a failure to maximize all of one’s time in the study of Torah)?’ He answered me immediately, ‘Whatever we are doing here in the seminar room is a fulfillment of talmud Torah (the study of Torah).’ There was a seamless connection in his eyes between his scholarly endeavors and the religious obligation to study Torah” (Horowitz 2015:259). 

Let us turn to a brief overview of the rise of historical-scientific Judaism to try better understand how R. Twersky could consider it part of the mitzva of Torah study. 

The rise of historical-scientific study of Judaism

Horowitz points out that since the time the Tanach (Hebrew Bible) was canonised, Jewish tradition has been unconcerned with historiography. Jews did not spend time writing history nor did they engage in its critical study. With few exceptions, the first time this omission began to be reversed was as late as the nineteenth century, during the Enlightenment period, by the Wissenschaft des Judentums. The Wissenschaft maintained that the vast span of Jewish history was not a singular event, as it was often perceived, but a series of progressive stages, during which time various influences waxed and waned and Judaism began to develop into the form it has today. This process, as one can understand, created challenges hitherto unexperienced: 

“The assumptions of objective historical research…have the potential of challenging the very foundations upon which religion rests” (Horowitz 2015:261). 

The problem with the Wissenschaft was that it was not entirely objective. Its aim was largely to reform Judaism. 

“The historicism of the Wissenschaft scholars was used purposively by them to undermine the legitimacy of the continuity of Jewish tradition” (Horowitz 2015:261). 

However, there were some substantial numbers of committed Orthodox scholars who were also part of this academic revival, developing a more traditional branch of the Wissenschaft, known as Chochmat Yisrael. It must be noted that although very few of these orthodox scholars would have met the “objective standards required in non-denominational universities,” nevertheless, it was the beginning of a new orthodox methodology and approach to academia. 

R. Twersky was the next step, Horowitz suggests, in refining that process, because now we have a Rebbe who is a Harvard Professor of Jewish History: 

“His own historical research was firmly and extensively built upon the results of Wissenschaft scholarship. That is not to say that in accepting the tools of scientific research, he agreed with the entire agenda of Wissenschaft… Although he worked from within the community of historically trained scholars, he used his critical facilities to correct misperceptions and to forge a new agenda in the writing of history” (Horowitz 2015:262). 


With R. Twersky’s meticulous attention to historical accuracy and detail, he had an understanding of the development of texts: 

“He read all of his texts with great precision, paying attention to the meanings and nuances of words in their context, as well as their use in respective time periods. The literary qualities of the text were also of great importance, as were the interconnecting webs of meaning and ideas that were represented in the text; its broader historical context rounded out his analysis…he would emphasize that there is still much to be done with the printed texts as they exist” (Horowitz 2015:263). 

Historic settings and cultures

R. Twersky was acutely aware that cultures exert different influences on the literature they produce. He writes that one must be cognisant of the fact that cultures create literary styles and that internal Jewish tensions of rationalism and mysticism are real forces to be reconned with. Additionally, the notion that religious politics is also a very real factor, was important to remember while trying to understand and analyse religious outlooks. Judaism is not static and unchanging. One had to be aware of: 

“[t]he confrontation of conventional cultural preoccupations with new secular learning, the relationship or integration of apparently disparate cultural disciplines, the role of charismatic and rationalistic forces within the framework of traditional communal institutions, personality clashes, and polemics.”[6] 

Horowitz explains how important context was to R. Twersky. He didn't just read a text to see who said what but he wanted to know why they said it: 

“His focus was the various ways in which philosophic ideas were received and studied, rather than the actual technical philosophic, kabbalistic, or exegetical positions taken by their respective adherents” (Horowitz 2015:265). 

Biographies of the rabbis

Biographies of the rabbis and sages and their religious profiles were important to be understood in their sitz im leben. When it came to Maimonides in particular, R. Twersky was careful to emphasize that the man, not just his words, also needed to be studied and analysed: 

“Not only have Jewish traditional characterizations blurred Maimonides’ individuality, but at times modern scholarship has also used uniform categories to describe him without addressing his uniqueness. A true, objective, unbiased account must be presented, and all the available material must be used, refraining from ahistorical, abstract categories that tend to impose preconceptions on Maimonides” (Horowitz 2015:265). 

Intellectual independence

R. Twersky demanded respectful and intellectual independence of the Torah scholar: 

“He implemented in his own writing the concept of melekhet shamayim, an approach that he claimed characterized the methodology of the Rishonim. The notion of melekhet shamayim requires one to express himself independently and creatively, without fear of articulating critical comments, and yet at the same time with deference, caution, and restraint” (Horowitz 2015:266).[7] 

This approach may also have been nurtured during his time at Boston Latin School which encouraged "dissent with responsibility."

Halacha and psak

R. Twersky’s views on Halacha reflect his historical approach too, but he was careful not to deal with the Halachic psak (legal praxis). Nevertheless, it was important to know how Halacha developed: 

“he asked a wide variety of questions, such as biographical, bibliographical, cultural, and literary questions, as well as ones regarding the place of halakha vis-à-vis other disciplines in the Jewish curriculum. These are questions which had not been asked of halakhic sources in the past” (Horowitz 2015:268). 

R. Twersky’s stance on a historic approach to Halacha, however, did not conform to the view of his beloved father-in-law, R. Soloveitchik, who clearly disapproved of such an approach. In R. Soloveitchik’s view: 

“The only effect that history has on halakha is that it provokes questions that arise from new situations… [Yet w]hile adhering to hasidic tradition and remaining personally, intellectually, and religiously close to his father-in-law, he never retreated from his historical methodology” (Horowitz 2015:277).[8] 

Which Maimonides?

When it came to the apparent dichotomy between the Halachic and philosophic Maimonides’ there was no issue because in the eyes of R. Twersky: 

“for Maimonides, the study of philosophy was an integral part of the mitzva of talmud Torah and its ultimate culmination… one could argue that there was a definite existential identification with Maimonidean positions – philosophic, spiritual, and, of course, halakhic – on the part of Prof. Twersky.” (Horowitz 2015:270). 

Rationalism or spirituality - an agonising choice?

R. Twersky saw no barriers between rationalist inquiry and spirituality. He writes: 

“It should be stated unequivocally that there is here no natural alliance between spirituality and anti-intellectualism, as is often the case in the history of religion. One way to achieve spirituality is by study, understanding, rationalization; emotionalism or “sensuousness” are not the exclusive, not even the preferred, means toward heightened sensitivity and spirituality. Rationalism and spirituality are congenial; the cognitive gesture is not only not antagonistic, but is conducive to sensitivity, subjectivity, and spontaneity.”[9] 

R. Twersky did not have to make an agonising choice between rationalism and spirituality because in his view rationalism was integrally related to spontaneity and spirituality. One could be a rationalist Maimonidean Chassidic Rebbe.

The Torah speaks in the language of humans

R. Twersky was not afraid to say things he well knew would be difficult for some religious people to hear. Here is one example of his formulation of the view of the fourteenth-century exegete, R. Yosef Ibn Kaspi, on the idea that dibra Torah kilshon benei adam (the Torah speaks in the language of humans). R. Twersky wrote: 

“Many scriptural statements, covered by this plastic rubric, are seen as errors, superstitions, popular conceptions, local mores, folk beliefs, and customs, statements which reflect the assumptions or projections or behavioral patterns of the people involved rather than an abstract truth. In its Kaspian adaptation, the rabbinic dictum may then be paraphrased as follows: “The Torah expressed things as they were believed or perceived or practiced by the multitude and not as they were in actuality.”[10] 

In other words, according to Ibn Kaspi, the sometimes strange and difficult cultural references in the Torah are not always to be taken as objective facts that we have to accept but as how they were seen at the time of its writing, reflecting the common beliefs and practices of that era. The Torah, in this view, speaks in the cultural language of its historical time. R. Twersky knew how hard these words would resound against those raised with the common notion of the Torah being timeless, but he did not shy away from expressing a contrary opinion as it was a sourced-based view by a rabbinic sage that needed to be heard alongside all other rabbinic views. 

Biblical and Talmudic Judaism

We mentioned earlier that R. Twersky never touched on matters of psak (legal praxis). There are other areas he did not delve into academically either and that was his views on biblical and Talmudic Judaism: 

“he did not deal with the biblical and talmudic periods, which would have required the historian to confront dogmatic aspects of Jewish tradition. Was this intentional? There is no question, as he himself once said in conversation, that a scholar has the right to choose his area of research. Once it is chosen, then his commitment to truth must be uncompromising. He chose the medieval period” (Horowitz 2015:278). 

This is why he focused on the rabbinic period of the Rishonim which extended between 1040 and 1500. Horowitz doesn’t elaborate on this but one wonders whether this isn’t an allusion to the idea that had R. Twersky confronted biblical source or historical criticism and the issue of Stammaim (Redactors) of the post-Talmudic period with his meticulous scholarly rigour, he would have similarly had to distance himself from that as he did with his reluctance to engage in the psak (praxis) of Halacha

Living in the tension of two worlds

A final interesting observation: Rebbe Professor Twersky chose to conduct his research in two notably secular academic institutions, Harvard and Hebrew Universities. He could have chosen religious academic institutions like Yeshiva University or Bar Ilan University. But perhaps his ability, if not need, to live within the tension of two different worlds simultaneously is the best way to understand the man. Perhaps for him, this choice was not just a strategy but indeed his ultimate purpose.

Further Reading
For another fascinating Chassidic personality within the Twersky family, see Kotzk Blog: 384) A rare glimpse into the critical mind of a Chassidic Rebbe – Yitzchak Nachum Twersky.

[1] Horowitz, C., 2015, ‘Halakha and History, Intellectualism and Spirituality: Professor Isadore (Yitzhak) Twersky’s Academic-Religious Profile Halakha and History, Intellectualism and Spirituality: Professor Isadore (Yitzhak) Twersky’s Academic-Religious Profile’, in Torah and Western Thought, Maggid Books, Jerusalem, 249-326.

[2] Twersky, I., 1975, ‘Harry Austryn Wolfson, 1887–1974’, Journal of the American Oriental Society, 95 (2): 181–183.

[3] Twersky, I., 1970, Mada’ei haYahadut beArtzot HaBrit, Jerusalem.

[4] Conclusion of the introduction to the Shemona Perakim, cited in Isadore Twersky, A Maimonides Reader (New York, 1972), 363.

[5] ‘Supplement: Isadore Twersky’, in Fox, Scheler, and Marom, Visions of Jewish Education, 91.

[6] Twersky, I., 1968, ‘Aspects of the Social and Cultural History of Provençal Jewry’, Journal of World History, 11, 187-8.

[7] See Twersky, I., 1980, Rabad of Posquières: A Twelth-Century Talmudist, revised ed., Philadelphia, 170-75.

[8] Parenthesis is mine.

[9] Twersky, I., 1974, ‘Religion and Law’, in Religion in a Religious Age, Edited by S. D. Goitein, Cambridge, 78 n6.

[10] Twersky, I., 1979, ‘Joseph Ibn Kaspi: Portrait of a Medieval Jewish Intellectual’, in Studies in Medieval Jewish History and Literature, Cambridge, 239-240.


  1. Is it clear that Rabbi Twersky z"l's formulation of Ibn Caspi was also his own position?

  2. Horowitz does bring another idea of Ibn Kaspi that he suggests R. Twersky would not have agreed with, but your question still stands. The answer, of course, is not clear and we can only surmise. I wouldn't want to put words in his mouth, but I can pose another question: Is it for reasons like this that he chose not to engage academically with certain periods because his commitment would have had to be uncompromising?