Musar literature is often described as "ethical literature." Professors Isaiah Tishby and Joseph Dan have described it more precisely as "prose literature that presents to a wide public views, ideas, and ways of life in order to shape the everyday behavior, thought, and beliefs of this public." Musar literature traditionally depicts the nature of moral and spiritual perfection in a methodical way. It is "divided according to the component parts of the ideal righteous way of life; the material is treated methodically - analyzing, explaining, and demonstrating how to achieve each moral virtue (usually treated in a separate chapter or section) in the author's ethical system."
Mishlei is commonly regarded as a mussar classic in its own right and is arguably the first true "mussar sefer." In fact, the Hebrew word ? (discipline, pronounced "mussar") being the title of this genre stems from the word's extensive use in the book of Mishlei.
You shall not take vengeance or bear a grudge against your kinsfolk. Love your neighbor as yourself: I am the LORD.
Hillel the Elder (c. 110 BCE - 10 CE), used this verse as a most important message of the Torah for his teachings. Once, he was challenged by a ger toshav who asked to be converted under the condition that the Torah be explained to him while he stood on one foot. Hillel accepted him as a candidate for conversion to Judaism but, drawing on Leviticus 19:18, briefed the man:
What is hateful to you, do not do to your fellow: this is the whole Torah; the rest is the explanation; go and learn.
Pirkei Avot is a compilation of the ethical teachings and maxims of the Rabbis of the Mishnaic period. It is part of didactic Jewish ethical Musar literature. Because of its contents, it is also called Ethics of the Fathers. The teachings of Pirkei Avot appear in the Mishnaic tractate of Avot, the second-to-last tractate in the order of Nezikin in the Mishnah. Pirkei Avot is unique in that it is the only tractate of the Mishnah dealing solely with ethical and moral principles; there is little or no halacha found in Pirkei Avot.
Medieval works of Musar literature were composed by a range of rabbis and others, including rationalist philosophers and adherents of Kabbalistic mysticism. Joseph Dan has argued that medieval Musar literature reflects four different approaches: the philosophical approach; the standard rabbinic approaches; the approach of Chassidei Ashkenaz; and the Kabbalistic approach.
Philosophical works of Musar include:
Rabbinic Musar literature came as a reaction to philosophical literature, and tried to show that the Torah and standard rabbinic literature taught about the nature of virtue and vice without recourse to Aristotelian or other philosophical concepts. Classic works of this sort include
Similar works were produced by rabbis who were Kabbalists but whose Musar writings did not bear a kabbalistic character: Nahmanides' Sha'ar ha-Gemul, which focuses on various categories of just and wicked people and their punishments in the world to come; and Rabbi Bahya ben Asher's Kad ha-Kemah.
Explicitly Kabbalistic mystical works of Musar literature include Tomer Devorah (The Palm Tree of Deborah) by Moses ben Jacob Cordovero, Reshit Chochmah by Eliyahu de Vidas, and Kav ha-Yashar by Zevi Hirsch Koidonover.
Chassidei Ashkenaz (literally "the Pious of Germany") was a Jewish movement in the 12th century and 13th century founded by Rabbi Judah the Pious (Rabbi Yehuda HeChassid) of Regensburg, Germany, which was concerned with promoting Jewish piety and morality. The most famous work of Musar literature produced by this school was The Book of the Pious (Sefer Hasidim).
Literature in the genre of Musar literature continued to be written by modern Jews from a variety of backgrounds.
Mesillat Yesharim is a Musar text published in Amsterdam by Moshe Chaim Luzzatto in the 18th century. Mesillat Yesharim is perhaps the most important work of Musar literature of the post-medieval period. The Vilna Gaon commented that he couldn't find a superfluous word in the first seven chapters of the work, and stated that he would have traveled to meet the author and learn from his ways if he'd still been alive.
Beginning in the eighteenth century, a number of Ottoman rabbis had undertaken the task of fighting the ignorance they believed was plaguing their communities by producing works of Jewish ethics (musar) in Judeo-Spanish (also known as Ladino). This development was inspired in part by a particular strain within Jewish mysticism (Lurianic Kabbalah) which suggested that every Jew would necessarily play a role in the mending of the world required for redemption. The spread of ignorance among their coreligionists thus threatened to undo the proper order of things. It was with this in mind that these Ottoman rabbis--all capable of publishing in the more highly esteemed Hebrew language of their religious tradition--chose to write in their vernacular instead. While they democratized rabbinic knowledge by translating it for the masses, these "vernacular rabbis" (to use Matthias Lehmann's term) also attempted to instill in their audiences the sense that their texts required the mediation of individuals with religious training. Thus, they explained that common people should gather together to read their books in meldados, or study sessions, always with the guidance of someone trained in the study of Jewish law.
Among the most popular works of Musar literature produced in Ottoman society was Elijah ha-Kohen's Shevet Musar, first published in Ladino in 1748. Pele Yoetz by Rabbi Eliezer Papo (1785-1826) was another exemplary work of this genre.
In Europe, significant contributions to Musar literature were made by leaders of the Haskalah. Naphtali Hirz Wessely wrote a Musar text titled Sefer Ha-Middot (Book of Virtues) in approximately 1786. Menachem Mendel Lefin of Satanov wrote a text titled Cheshbon Ha-Nefesh (Moral Accounting) in 1809, based in part on the ethical program described in the autobiography of Benjamin Franklin.
One form of literature in the Hasidic movement were tracts collecting and instructing mystical-ethical practices. These include Tzavaat HaRivash ("Testament of Rabbi Yisroel Baal Shem") and Tzetl Koton by Elimelech of Lizhensk, a seventeen-point program on how to be a good Jew. Rabbi Nachman of Breslov's Sefer ha-Middot is a Hasidic classic of Musar literature.
The modern Musar movement, beginning in the 19th century, encouraged the organised study of medieval Musar literature to an unprecedented degree, while also producing its own Musar literature. Significant Musar writings were produced by leaders of the movement such as Rabbis Israel Salanter, Simcha Zissel Ziv, Yosef Yozel Horwitz, Yisrael Meir Kagen, and Eliyahu Dessler. The movement established Mussar learning as a regular part of the curriculum in the Lithuanian Yeshiva world, acting as a bulwark against contemporary forces of secularism.