Envisioning the World in the Middle Ages
De Sphaera Mundi
Medieval science was strongly influenced by the works of Aristotle, whose work became known in the Christian west through Islamic and Jewish scholars and scientists, many of whom were working in al-Andalus, later Spain.
The works below by Aristotle, Alfonso X, and Sacro Bosco, printed in the fifteenth and sixteenth centuries, reflect this heritage.
Aristotle's Physica depicts the Sphera Mundi, a Ptolemaic, geocentric vision of the universe. Writing in the 4th century BCE, Aristotle proposed that 55 concentric celestial spheres were made up of the moon, planets, sun, and stars, encircling the earth at the center.
Special Collections' edition, bound in the sixteenth century with other works by Aristotle, is heavily annotated by a sixteenth- or early seventeenth-century hand and doodles, as well as a later hand, a testament to Aristotle's enduring relevance to discussions of astronomy and physics, nearly two millennia after his death.
Alfonso X. Alfontij Regis Castellae Illustrissimi Caeslestium Motum Tabule. [Venice]: Erhard Ratdoldt, 1483.
Alfonso X of Castile commissioned the Alfonsine Tables in the mid-thirteenth century. The Tables were based on earlier astronomical observations and writings by Islamic and Jewish scholars: Yehuda be Noshe, Isaac ibn Sid, and others.
The first printed edition, seen here, was published in 1483 by Erhard Ratdolt, who was also responsible for the earliest publication of Euclid (1482). Ratdolt was perhaps the first printer/publisher of scientific or mathematical works, all elaborately illustrated with detailed woodcuts and decorative initials.
The Alfonsine Tables track the locations of planets at specific times and the times of eclipses. The earliest observations date from 1 January 1252. The Tables were highly influential even as late as the sixteenth century; Nikolaus Copernicus used parameters derived from them in his Commentarioulus, first circulated in Latin by 1514.
Special Collections' copy of the Alfonsine Tables is especially interesting for its original, hand-tooled, chained binding with brass clasps and bosses; the hole in the back cover was used to chain the book to a library shelf, a medieval and early-modern means of preventing the theft of a library’s most valuable treasures. One leaf (seen here) shows a fifteenth-century version of a sticky note fashioned of a medieval manuscript fragment and attached with thread.
Johannes de Sacro Bosco. Iohannis de Sacro Busto Libellus de Sphaera. Wittenberg: Philippi Melanthonis, 1574. Gift of Sam Tour.
Johannes de Sacro Bosco. Sphaera Ioannis de Sacrobvsto. Venetiis: Heredem Ioannem Patauinum, Expensis Melchioris Sessae, .
Scottish or British(?) mathematician Johannes de Sacrobosco (John Holybush) worked in Paris in the early thirteenth century. Like the authors above, his De Sphaera Mundi reflects a Ptolemaic view of the universe and the work of Islamic astronomers.
De Sphaera formed the foundation for medieval astronomical and cosmological education. It begins with a discussion on spheres and their properties, followed by discussions on planetary motion and the causes of eclipses.
Like Aristotle's universe, Sacrobosco’s system was geocentric; the unmoving Earth was the center. His work was gradually superseded by Copernicus’ study, De Revolutionibus, which argued for a heliocentric system. Special Collections 1574 edition, Iohannis de Sacro Busto Libellus de Sphaera, attests to the work's enduring use as a text book, even in the years following the publication of Copernicus' work in the 1540s.
Special Collections’ 1557 edition, published in Venice, shows a worm hole (see left) created by an intrepid bookworm at some point in the book's past.
Special Collections 1574 edition, published in Wittenberg, Germany with a preface provided by the Protestant reformer, Philip Melanchthon, is unique for its cover (below, right). It is fashioned of a re-used medieval manuscript, possibly a work on the life of Dionysius the Areopagite, a convert to Christianity in 1st century Athens.
Both editions feature extensive woodcut illustrations of the spheres, eclipses, the motion of the planets, and the signs of the zodiac.
Hartmann Schedel. Liber Chronicarum. Nuremberg: Anton Koberger for Sebald Schreyer and Sebastian Kammermeister, 12 July 1493.
On the eve of the sixteenth century, notions of the earth's place in the solar system continued to locate it at the center, as seen in this Creation scene, the spheres of planets, sun, and stars surrounding the earth. This woodcut appeared in Hartmann Schedel's Liber Chronicarum, published in 1493.
The Prussian mathematician and astronomer, Nicolaus Copernicus, was then twenty years old. His manuscript, Commentariolus, which contradicted centuries of geocentrism with his heliocentric vision of the solar system, would begin to circulate just two decades in the future, in 1514.