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 Musar literature 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 Musar literature Philosophical works of Musar include: Chovot ha-Levavot by Bahya ibn Paquda Hilchot Deot in Sefer ha-Madah of Mishneh Torah by Maimonides Sefer Hayashar (the ethical work, not to be confused with the many other unrelated works of the same name), published anonymously Shemona Perakim ("The Eight Chapters"):, the introduction to Pirkei Avot in Maimonides' commentary to the Mishnah. Standard Rabbinic Musar literature 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 Ma'alot ha-Middot by Rabbi Yehiel ben Yekutiel Anav of Rome Shaarei Teshuvah (The Gates of Repentance) by Rabbi Yonah Gerondi Menorat ha-Ma'or by Israel Al-Nakawa b. Joseph of Toledo Menorat ha-Ma'or by Isaac Aboab Orchot Tzaddikim (The Ways of the Righteous), by an anonymous author Meneket Rivkah by Rebecca bat Meir Tiktiner 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. Medieval Ashkenazi-Hasidic Musar literature 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). Medieval Kabbalistic Musar literature 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 Tzvi Hirsch Kaidanover. Modern Musar literature Literature in the genre of Musar literature continued to be written by modern Jews