Rabbi Joseph ben Abba Mori Caspi was born in L'Argentiere, in South France, over 650 years ago. His name Caspi ("The Silver One") is derived from the name of his native city, which in French means "silver."

From his early years, he distinguished himself with his unusual mental capacity and his great diligence and intensity in Torah study. At the age of 17, he started compiling books, and he wrote at that time a commentary on Rabbi Abraham Ibn Ezra's commentary on the Torah. He also wrote a commentary on the Sefer HoRikmoh by Rabbi Jonah Ibn Janach.

He left his birthplace and travelled for a long time in search of a Rabbi from whom to learn more Torah and more wisdom. He also visited Egypt, where the great-grandchildren of the great Rambam lived. Rabbi Abraham Maimon (the 2nd), a grandson of the Rambam's son Abraham, and the other great-grandchildren of the Rambam were truly fine Rabbis, scholars and pious men. After staying in Egypt for five months, Rabbi Joseph returned to France and settled in the town of Tarrascun.

At that time the terrible attacks, known as the "Shepherds' Uprisings," broke out in South France. A fanatical Christian shepherd had gathered around him a group of shepherds and bandits, and they carried out brutal massacres of Jews in the name of a "divine mission." No sooner had this tragic episode ended, than the Black Plague broke out, and Jews were falsely accused of having thrown poison into the wells, in an effort to wipe out the Gentile population. Although many Jews themselves died from the Plague, and the whole accusation was as absurd as it was cruel, it still served as an excuse to kill and rob the unfortunate Jews. The young scholar, Rabbi Joseph Caspi also fell into the hands of these murderers, and had to choose between conversion and death. Rabbi Joseph was ready to sacrifice his life for Kiddush HaShem, but at the last minute his life was miraculously saved. From that time on, he immersed himself even more in the study of the holy Torah. He made it his goal to write a commentary on the whole Tanach. He also delved into the philosophical works of the Rambam and other great Jewish scholars, and he continuously wrote books and interpretations.

In order to satisfy his great thirst for Torah and knowledge, and for the secrets of the Torah, he started on his way once more. He visited Castille, Aragon and Valencia in Spain, and also the island of Majorca near the Spanish shore. Everywhere he drank deeply of the great fountain of knowledge possessed by the great Torah scholars in these places.

He spent 6 months in Majorca, and he wrote his work Gelilei Kesef in the year 5091 (1331), out of gratitude to the community leaders there, who had received him so warmly. A year later, in Valencia, he completed his Sefer HaMussar and sent it to his son Solomon, a boy of 12, whom he had left in Tarrascun. It was a "Tzavooh" (a spiritual will) to him, as to how he should conduct himself throughout his life.

On the whole, Rabbi Joseph Caspi had a very difficult life. Apart from the difficulties he experienced in his many wanderings, he also was not happy about the opposition of some scholars to some of his writings. The reason for this was that on the one hand, Rabbi Caspi was quite outspoken against the Jewish intellectuaIs of his time, who spent too much time on secular studies at the expense of the study of the Torah. On the other hand, he was often opposed by great Torah scholars for expressing certain philosiphical ideas which they felt could be easily misunderstood by young scholars and students. Such writings could therefore give them wrong ideas, and distort their outlook on life. As was the case with many other Jewish philosophers, Rabbi Caspi relied too often on his own intellect, and tried to explain many things pertaining to belief which are beyond the grasp of the human brain. Because of this, many great Torah scholars of his time, and after his time, spoke out sharply against his views. Thus, Rabbi Caspi did not derive too much enjoyment from either side. Rabbi Joseph, however, continued his writing and his studying.

Although he did not reach an advanced age - he died at the age of 43 - he wrote tens of books. Most of them have the word "Kesef" in their title, because of his name Caspi. A number of his works were published later; some remained in manuscript form, and many were lost. He wrote on many subjects: on the Hebrew language and grammar, explanations of the Tanach, religious philosophy and on the mysteries of the Torah.

One of his most important works that has been published many times is the above-mentioned Sefer HaMussar (also known as Yore Deah, but not to be confused with the section of the Shulchan Aruch bearing the same title), which he wrote at an early age for his son, "not knowing what the times may bring, because of the persecutions in general, and especially because of my own wanderings." In this book the father gives advice to his young son and encourages him to always remain true to the holy Torah, to walk in the path of the Almighty, and to always seek the truth, because, "the truth has to fear, or be ashamed of, no thing." He also tells him what to learn in order to elevate himself in Torah and in general wisdom according to his years. Among Rabbi Joseph Caspi's other works are the following:

Resukos HaKesef - a Hebrew grammar

Sharsheros HaKesef - grammatical derivatives in the Hebrew language

Metzoref LaKesef - an interpretation of the Torah

Mezamros Kesef - on Thillim (Psalms) Mitos Kesef-on Neviim (Prophets)

Chatzotzeros Kesef - on Shir HaShirim (Song of Songs), Mishlei (Proverbs) and Koheles (Ecclesiastes)

Kapos Kesef - on Ruth and Eichoh (Lamentations)

Gelilei Kesef - on Esther

Chaguras Kesef - on Ezra and Divrei HaYomim (Chron.)

Kaaras Kesef - on Daniel

Tiras Kesef (Sefer HaSod) - on secrets of the Torah

Amudei Kesef and Maskiyo Kesef - on the Rambam's Moreh Nevuchim (Guide to the Perplexed)

and many other works.

The author of these many works, Rabbi Joseph Caspi, well knew the weak points of some of the views expressed in his philoscphical works, and he did not expect them to be accepted without question. He also knew that the human intellect can fail entirely when trying to comprehend areas that stand higher than intellect. He therefore writes (in Sefer HaMussar, Ch. 13): "If, Heaven forbid, someone will find in my books a doubtful idea, he should throw it out, as Rabbi Meir used to do, taking for himself the kernel and throwing away the shell." In other words, he urged his readers to accept the good points and disregard anything which is doubtful in his works. Rabbi Joseph Caspi was thus not only a great Torah scholar, but also a humble one. Indeed, Torah scholarship and humility are inseparable.