The main focus of this book is the study of Abraham Ibn Ezra's (1089-1167) scientific thought within the historical and cultural context of his times. His scientific contribution may be understood as the very embodiment of 'the rise of medieval Hebrew science', a process in which Jewish scholars gradually adopted the holy tongue as a vehicle to express secular and scientific ideas. The first part provides a comprehensive picture of Ibn Ezra's scientific corpus. The second part studies his linguistic strategy. The third and fourth parts study Ibn Ezra's introductions to his scientific treatises and the fifth part is devoted to studying four 'encounters' with Claudius Ptolemy, the main scientific character featuring in Ibn Ezra's literary work.