Moses ben Joshua, also known as Moses of Narbonne, Maestro Vidal Blasom, and Moses Narboni, was a medieval Catalonian philosopher and physician. He was born at Perpignan at the end of the thirteenth century and died sometime after 1362. He began studying philosophy with his father when he was thirteen and then studied with Moses and Abraham Caslari. He studied medicine and eventually became a successful physician, and was well versed in Biblical and rabbinical literature.
Eventually he traveled to Spain, where he is known to have lived and studied in Toledo, Soria, and Valencia. During the outbreak of the Black Death when persecution of Jews was widespread, ben Joshua was forced to flee Cervera when an angry mob attacked the Jewish community there.
Moses was an admirer of Averroes; he devoted a great deal of study to his works and wrote commentaries on a number of them. Perhaps ben Joshua's best know work is his Treatise on the Perfection of the Soul.
He believed that Judaism was a guide to the highest degree of theoretical and moral truth. In common with others of his era he believed that the Torah had both a simple, direct meaning accessible to the average reader as well as a deeper, metaphysical meaning accessible to thinkers. He rejected the belief in miracles, instead believing they could be explained, and defended man's free will by philosophical arguments.
He died at an advanced age as he was returning to his native land from Soria.