The Astrological Texts of King Alfonso X of Spain, and His Contribution to Modern Science

Abstract

In modern Western society the study of astrology is not taken seriously by the majority of people. However, in the medieval period astrology was held to be a hard science. Astrology was studied in the East long before it came to be pursued by Western scholars. The 8th century A.D. Moslem invasion of Spain meant that much of this knowledge was brought to Europe. One of the key figures in the reacquisition of this knowledge was King Alfonso X, known as El Sabio, or The Wise, for his love of learning. Shortly after his coronation he established groups of translators at his court in Toledo who were responsible for translating texts from their original language into Spanish. The majority of the works he ordered to be translated were Eastern texts on the sciences, the majority of Arabic origin. In particular he had a great interest in the study of astrology, and included many Eastern astrological texts in his library. In addition to translation Alfonso occasionally expanded upon the work of the Eastern scholars, contributing his own observations to theirs. In this paper I give an overview of the contributions Alfonso made to the study of astrology, with particular focus placed upon two of his works: Lapidario, and Libro de formas e ymagenes, both of which study the relationship between astrology and stones. These texts demonstrate scientific experimentation and analysis in its earliest stages and by studying these documents, the role of Alfonso X in the development of modern Western science can clearly be seen.