In the Middle Ages, Greek philosophy was highly influential among Arab scholars. Likewise, there were many Jewish scholars who together developed a similar, Jewish branch of philosophy. The defining factor of Jewish philosophy, in contrast to general philosophy, is the extent to which Jewish sources influence its content. Furthermore, Jewish philosophy is concerned with questions that are unique to Jewish life. It addresses matters that are pertinent in the realm of Jewish thought, such as providence, revelation, the chosenness of the Jewish people, reward and punishment, explanations for the mitzvot, and the divinity of the Torah. Nevertheless, Jewish philosophy was influenced by general philosophical thought as well, and adopts some of its theories.

Rav Se’adya Gaon (882–942) was born in Egypt, studied in the Land of Israel, and was appointed as head of the academy in Sura, Babylonia. He was involved in a number of controversies in his day: He disagreed with the geonim of the Land of Israel concerning the fixing of the Jewish calendar, struggled against the Exilarch in Babylonia concerning matters of authority, and opposed the Karaites concerning the status of the Oral Torah.

He was a prolific writer, leaving us with many books in a variety of fields. He translated the Torah into Arabic, and wrote a commentary on the Torah and on several books of the Prophets and Writings. He also wrote a dictionary and a book of Hebrew grammar, arranged the ritual prayers in his siddur (prayer book), and wrote liturgical poetry. He created an organized, systematic theory of Jewish philosophy in his work Emunot VeDe’ot and in his commentary to Sefer Yetzira. He also wrote several important works of halakha, such as Sefer HaShetarot and Sefer HaYerushot.

Rav Se’adya was a groundbreaking leader who understood the issues facing his generation. Through his actions and innovations he shaped Jewish life at that time. His varied undertakings brought Torah to the people and strengthened Jewish traditions. His linguistic works enabled Arabic-speaking Jews, who did not have a strong grasp of Hebrew, to study Torah. His philosophical works demonstrated the biblical basis for Jewish philosophy. Additionally, he was a strong opponent of the Karaite position.

Rav Se’adya’s works made their mark on later generations as well. Terms that he coined, such as the distinction between rational mitzvot [mitzvot sikhliyot] and mitzvot of compliance [mitzvot shimiyot], remain in use. Matters that he determined to be significant, such as the status of humankind in the world, are still discussed. His philosophical method, which relies on tradition on one hand, and on logic and understanding on the other, is still employed.

From Rav Se’adya Gaon:

The purpose of Creation is for our world. Look at all of its parts; the land and the water are both inanimate, and the animals do not speak. This leaves only humankind as its purpose.

Rav Yehuda HaLevi (1075–1141) was born in Tudela, Spain, and died in Jerusalem. A poet, philosopher, and doctor, he was an associate of the poets Rav Moshe ibn Ezra and Rav Avraham ibn Ezra. He wrote hundreds of poems, both religious and secular, which are published in the anthology Diwan. Some of his poems can be found in the prayer book, and some have even been set to music and are sung on Shabbat.

His philosophical work is called The Kuzari. Its purpose was to defend the Jewish faith from the criticisms of Christians, Muslims, and Karaites. It takes the form of a dialogue between a Khazar king and a rabbi. The latter explains the shortcomings of Aristotelian philosophy and the flaws in Christian and Muslim beliefs, demonstrating, by contrast, the merits of the Jewish faith. The frame story is based on the well-known legend that the king of the Khazars and his subjects converted to Judaism. The book asserts that Jewish faith is based on prophetic, spiritual revelation, and it understands Jewish history, and the longed-for redemption, on the basis of this assumption. The writer maintains that Judaism did not lose its prophetic, messianic vision, even while the Jews were living under Arab and Christian rule.

Rav Yehuda HaLevi ultimately fulfilled his dream of reaching Jerusalem. Legend has it that as he prostrated himself beside the Temple Mount, he was trampled to death by an Arab horseman.

From Rav Yehuda HaLevi:

Israel among the nations is like the heart among the organs; it is the sickest of them all and the healthiest of them all.

Rambam (1135–1204) was born in Cordova, Spain, lived in Fustat, Egypt, and was buried, according to tradition, in Tiberias. He wrote several significant works of commentary and halakha. As a young man he began writing his commentary on the Mishna, which includes a number of important introductions: introduction to the Mishna, which is concerned with the relationship between the Written Torah and the Oral Torah; introduction to Avot, which deals with ethical and moral behavior; and introduction to Ĥelek, the final chapter of tractate Sanhedrin, which is about the interpretation of aggadot, i.e., non-halakhic statements of the Sages, and the basic principles of faith.

His Sefer HaMitzvot lists all the Torah commandments, and lists the principles for determining which are derived from the Torah and which are rabbinic law. His Mishne Torah is a code of Jewish law, and was the first of its kind. It contains final halakhic rulings drawn from the many disagreements found in the Mishna and in extensive discussions in the Talmud. It even addresses the mitzvot that are not applicable in our time. The work is intended for one who wishes to know the halakha without having to learn other sources beforehand.

Rambam also wrote a work of philosophy, called Guide of the Perplexed, which interprets the Torah and the mitzvot from the perspective of philosophy. One of the notions that he upholds is that of negative conceptions: One must not describe God in any positive terms, but only by negating descriptions, because one cannot attribute human qualities to Him. The book was widely criticized because of its attempt to provide purely philosophical justifications for the mitzvot. For this reason, some opposed Rambam and banned his works.

Rambam was a doctor, and in his medical writings he emphasized the importance of healthy eating as a way of preventing illness. He was the leader of the Jewish community in Egypt and provided support to the Jews of Yemen when they faced adversity. He also maintained strong ties with the rabbis of Lunel and Marseille, in the south of France. Rambam’s influence on his generation was immense, and his works and ideas became prized assets for all future generations of the Jewish people.

From Rambam:

The perfection in which a person can truly take pride is attained by him when he has acquired, as far as it is possible for a human being, the knowledge of God, the knowledge of His providence, and of the manner in which it influences His creatures in their creation and continued existence. Having acquired this knowledge he will then be determined always to seek loving-kindness, judgment, and righteousness, and thus to imitate the ways of God. 

Rav Yaakov Anatoli (1194–1256) was born in Provence, lived in Naples, and made his living as a translator, in addition to being a doctor. He was the son-in-law of the translator Rav Shmuel ibn Tibon. His work Malmad HaTalmidim, is divided into chapters following the order of the weekly Torah portions, and offers rationalistic, Maimonidean interpretations of the Torah. In this work, he encourages his readers to study philosophy, and interprets biblical verses in accordance with their philosophical significance.

Rav Anatoli maintained friendly ties with gentile scholars. He exchanged ideas with them and even cited some of them in his commentary on the Torah. He translated Aristotle’s works on logic from Arabic into Hebrew.

From Rav Yaakov Anatoli:

One must examine a statement in and of itself, and not in relation to who said it. You see that Moses our teacher placed the section concerning Yitro before the section describing the giving of the Torah, because Moses valued Yitro’s advice.

Ramban (1194–1270), a physician by trade, was born in Girona, Catalonia, Spain, and died in Jerusalem. His commentary on the Torah is comprehensive and deep, giving original explanations on all four levels of interpretation: plain meaning (peshat), allusion (remez), exegesis (derash), and concealed meaning (sod). His Talmud commentary attests to his sharp analytical skills and to his mastery of both the Babylonian Talmud and the Jerusalem Talmud. He was the first to integrate into his commentary the explanations of the Babylonian geonim, of Rashi and Tosafot from the lands of Ashkenaz (western Europe), and of the halakhic authorities of Spain.

In the realm of halakha, Ramban’s book Milĥamot Hashem defends Rav Yitzĥak Alfasi, known as Rif, from the criticisms of Rav Zeraĥya HaLevi. Ramban also wrote a criticism of Rambam’s count of the 613 mitzvot in Sefer HaMitzvot. Ramban’s main halakhic work is Torat HaAdam, which is concerned with matters of burial and mourning. His main philosophical work is Sha’ar HaGemul, about reward and punishment.

His writings do not contain many explicit kabbalistic ideas. He was careful to keep his kabbalistic wisdom concealed, revealing it only through allusions, which he generally prefaces with the phrase “in the way of the truth.” Nevertheless, it is believed that he studied Kabbala and was in contact with the kabbalists of Girona. Ramban took part in the Disputation of Barcelona, debating a Jewish apostate named Pablo Christiani. After Ramban’s decisive victory, documented in Sefer HaVikuaĥ, which contains the transcript of the debates, he was compelled by the authorities to flee, and he immigrated to the Land of Israel.

From Ramban:

Everything that occurred to the patriarchs is a sign for their descendants. This is why the verses provide a lengthy description of their journeys and their digging of wells and other incidents. One who reflects upon these passages may think that they are superfluous and insignificant, but they serve to teach about the future.

This work enumerates the Torah commandments, arranged according to the weekly Torah portions. The book has been attributed to Rav Aharon HaLevi (1235–1303), or to his brother, Rav Pinĥas HaLevi, though not conclusively. The book’s objective was to educate youngsters who had reached the age of mitzva observance to learn the 613 mitzvot. The work is based on Rambam’s count of the commandments in Sefer HaMitzvot. For each mitzva, the writer lists its source in the Torah, its main halakhot, to whom it applies and when, and its reasons. The reasons for the mitzvot are called its “roots,” because their objective is not to justify a particular mitzva, but to deepen its significance in the human experience. For example, when discussing the reasons for the many mitzvot related to the exodus from Egypt, the writer coined the phrase, “Our hearts follow our actions” (mitzva 16). Likewise, he often explains the reason for a mitzvah as being “to make a strong impression and affix a lesson in our minds.” Although the book was ostensibly intended for educators, it is widely studied and has made a significant contribution to halakhic discourse.

From Sefer HaĤinnukh:

One must know and fully believe that everything that occurs to a person, both good and bad, comes to him from God. Even with regard to circumstances that are brought about by the hand of another person, by someone acting against another, nothing occurs that is against God’s will.

Rav Ĥasdai Crescas (1340–1410) was born in Barcelona and died in Saragossa, Spain. He participated in numerous disputations, debating representatives of the church, and wrote a book refuting the principles of the Christian faith.

His philosophical approach is considered to be original and innovative. He maintained that faith in God stems from emotion rather than from the intellect, and that the notion of free will contradicts that of God’s foreknowledge. He criticized Aristotelian science, which was accepted at the time, and it seems that much of his thinking was influenced by the Kabbala. His complex ideas are presented in his book, Or Hashem. Some see this work as a harbinger of the scientific revolution of the seventeenth century, and of the epistemology of the eighteenth century.

His son was killed in the 1391 Spanish pogroms, and evidently, this influenced Rav Crescas’s worldview.

From Rav Ĥasdai Crescas:

It is incontrovertible that the One who acts is also One who knows, desires, and is able, and the one who is acted upon desires and makes choices…. It is incontrovertible that there is some relationship and connection between God and people, and this connection is prophecy.

Rav Yosef Albo (1380–1444) served as the rabbi of the communities of Aragon and Castile, Spain. His book, Sefer HaIkkarim, consolidates Rambam’s principles of faith and those of Rav Ĥasdai Crescas, who was Rav Albo’s teacher, into three central principles of faith: the existence of God, the divinity of the Torah, and reward and punishment. He asserts that it is possible to derive all other Jewish beliefs from these three. The book’s clear and straightforward style led to its widespread reputation as an essential work on Jewish beliefs.

Rav Albo participated in the Disputation of Tortosa, defending the Jewish faith against representatives of the church. Unlike other rabbis, who were concerned about possible repercussions, he dared to criticize Christian theology.

From Rav Yosef Albo:

Though it is not the way of the bee, according to its nature, to have the understanding to build those cells of wax, where the honey is collected, in the shape of a hexagon, God gave it the understanding to build them in this shape, which is similar to a circle, which is the natural shape…. All this is found in the bee because it is God’s work…. This is the pleasantness of work that is in fact brought about by the Divine.

Rav Yitzĥak Arama (1420–1494) was born in Spain and lived in a number of different Spanish communities before settling in Calatayud. He died in Naples, following the expulsion of the Jews from Spain. His book Akedat Yitzĥak is a collection of sermons, each of which connects a verse from the weekly Torah portion with an idea from the Zohar and a philosophical concept. This work was widely praised, both for its content and for the structure of the sermons, which, for many generations, was considered the only acceptable structure for sermons. While the ideas in the book are based on those of Rambam and the Zohar, the use of a philosophical framework for the commentary recalls the style of the sermons given by priests in church, which every Jew was obligated to listen to according to Aragonese law.

From Rav Yitzĥak Arama:

The maidservant [i.e., philosophy] will accomplish as much as she can, and the mistress [i.e., Torah] will remain seated under her canopy. When the maidservant finds favor in the eyes of those who see her, and they elevate and honor her, and begin to believe that she is the one in charge, and they bring the mistress before the maidservant to do her work, then the Torah will fade away and there will be great crying out and grieving.

Mabit (1500–1580) was born in Thessaloniki to a family of Spanish exiles, and moved to Safed at a young age. There he was appointed as a judge in the religious court of Rabbi Yaakov Beirav. He served in this role, alongside Rabbi Yosef Karo, for fifty-four years. His important works are Responsa of Mabit, which contains his answers to eight hundred questions in all areas of halakha; Kiryat Sefer, which discusses whether the sources of halakhot are from the Torah or the Sages; and Beit Elohim, which contains topics of Musar, Jewish thought, and prayer.

While Mabit and Rabbi Yosef Karo respected and admired one another, they disagreed with regard to many halakhic matters. Their dispute concerning the halakhot of the Sabbatical Year is well known. While Rabbi Karo was influential in Safed and the rest of the Land of Israel, Mabit was considered an important authority throughout the Ottoman Empire, and was asked to decide disputes and questions that were brought to him from far and wide.

From Rabbi Moshe of Trani:

The purpose of prayer is not to be answered, but to teach us that there is no one in the world to whom it is proper to pray other than to God. One must recognize that a person has nothing in this world, and that there is no one who can fulfill his needs other than God.

Maharal (1520–1609) was born in Poznan, Poland, and served as the rabbi of Nikolsburg. Later he became the leader of the Jewish community of Prague, which is where he died. He was a prolific author, and his writing is methodical and comprehensive. His book Gur Arye is a commentary on Rashi’s commentary on the Torah, Netivot Olam is a work of Musar, Tiferet Yisrael discusses the importance of the Torah, Netzaĥ Yisrael is concerned with exile and redemption, Gevurot Hashem is about the exodus and the festival of Passover, and Ner Mitzva is about Hanukkah. He also wrote a systematic commentary on the talmudic aggadot.

His writing is remarkable for its breadth, as it covers a wide range of subjects and covers each subject extensively; for its length, as it relates to every angle of the subject; and for its depth, as his thinking is original and daring.

Maharal represented the Jewish community to the authorities, and thanks to his knowledge of the philosophy and science of the time, he became friendly with Rudolf II, king of Bohemia, and possibly with Johannes Kepler as well.

Maharal sought to change the prevailing method of Torah study, which involved studying Talmud via the method of pilpul, i.e., intricate and at times exceedingly complex analysis. Instead, he favored an organized system of study that would lead to the mastery of Bible, Mishna, and Talmud. To this end, he instructed his student Rabbi Yom Tov Lipmann Heller to write the commentary on the Mishna, Tosefot Yom Tov. He also encouraged the study of Mishna in groups. In the nineteenth century, his name became associated with the legend of the Golem of Prague.

From Maharal:

Therefore, the name “Torah” is fitting for the Torah, as it comes from the term “teaching” [hora’a], and the Torah teaches a person the ultimate objective to which he should aspire.

Rabbi Menaĥem di Lonzano (1550–1626) was born in Italy or Turkey, lived in a number of different places, and immigrated to Jerusalem. He wrote the book Shetei Yadot, which contains two parts: Yad Ani and Yad HaMelekh. He divided each part into five separate sections, corresponding to the five fingers on each hand. These writings include linguistic materials, liturgical poetry, and Kabbala.

Some of the sections in the first part include: Or Torah, the Masoretic text of the Torah; HaMa’arikh, a completion of the dictionary HeArukh; and Avodat HaMikdash, a liturgical poem that describes the Temple service. The second part includes a collection of aggadic midrashim, which he published in accordance with manuscripts that he possessed.

He suffered greatly during his life. He was orphaned at a young age and lived his entire life in poverty. He suffered from personal attacks and had physical difficulties ranging from problems with his feet and blindness in one eye.

He was bold, and did not hesitate to disagree with Ramak, the Ari, and Rabbi Ĥayyim Vital in kabbalistic matters, nor to criticize Rabbi Yisrael Najara for not revealing that he borrowed entire passages from Arabic poetry that Rabbi Menaĥem di Lonzano considered inappropriate for religious poetry.

From Rabbi Menaĥem di Lonzano:

Although I am obligated to honor the ones with whom I disagree, both they and I are obligated to honor the truth.

Rabbi Azarya Figo (1579–1647) was born in Venice, served as the rabbi of Pisa, and died in Rovigo, Italy. He wrote the book Giddulei Teruma, a commentary on Sefer HaTerumot by Rav Shmuel of Sardinia, which deals with monetary cases in Jewish law. Rabbi Figo’s prodigious scholarship is apparent from the fact that when he wrote Giddulei Teruma, he hardly had any books at his disposal. Bina LeIttim is a collection of his sermons on the festivals, in which his brilliance, mastery of the Bible, and exegetical skill are demonstrated. This book has continued to be popular among preachers throughout the generations. As was customary among Italian Jews, Rabbi Figo studied at the University of Venice and subsequently devoted himself to Talmud study.

From Rabbi Azarya Figo:

Freedom is, by nature, much yearned for, not only by humankind, but even by animals, which cannot speak. All creatures instinctively become distressed and afraid when they are enslaved by another, and it turns their joy into sorrow…. All the more so, humans cannot bear the burden of enslavement to others. For this reason, the hatred of Joseph’s brothers toward him grew.