In knowledge and sharp-witted understanding of the Talmud, these four Isaacs were outstripped by the fifth, Isaac ben Jacob Alfassi, or Alkalaï. Born in Kala-Ibn-Hammad, in the neighborhood of Fez (1013), he was instructed by the last African authorities, Nissim and Chananel, and after their death in 1056 he became the representative of Talmud studies in western Africa. Indifferent to the scientific pursuits which their taste as well as consideration for their material advancement prompted the gifted Jews of Spain and Africa to cultivate, Alfassi devoted all his acumen to a profound study of the Talmud. His was a deeply earnest, independent nature, not content to keep to the beaten track of time-honored customs, but desirous of striking out into new paths. It had hitherto been the custom to follow in practice the rulings of the Geonim, whenever, as frequently occurs, the Talmud records conflicting opinions on a given subject, and to accept their explanations and decisions as norms. Alfassi, however, proceeded from the commentaries to the text itself, and sought with his peculiar acuteness to distinguish all that was incontestable and durable, and of real import, in the Talmud, from that which was doubtful, superficial, and expedient. The opinions of the Gaonic authorities were not final for him. In this spirit he compiled a work, which, in spite of the attacks leveled at it at the time, became a standard book for the entire Jewish community. His "Halachoth" abstract from the Talmud only whatever affects conduct, but fix the practical bearings of the laws thus classified with absolute certainty. Alfassi's work consigned to oblivion all similar works compiled in the course of three centuries, since Jehudaï Gaon's time. His name was borne by this work far beyond the straits into Spain where he counted still more admirers than in his native land. A complete match for Alfassi, however, in knowledge of the Talmud was the Frenchman, Solomon Yizchaki, a man as acute and independent as himself, only less bold and impetuous, but more versatile.