Secretum Secretorum

Modern scholarship considers that the text must date to after the Encyclopedia of the Brethren of Purity and before the work of Ibn Juljul in the late 10th century.

The first Latin translation of a part of the work was made for the Portuguese queen c. 1120 by the converso John of Seville; it is now preserved in about 150 copies under the title Epistola Aristotelis ad Alexandrum de regimine sanitatis ("Aristotle's letter to Alexander on good health").

Its topics range from ethical questions that face a ruler to astrology to the medical and magical properties of plants, gems, and numbers to an account of a unified science that is accessible only to a scholar with the proper moral and intellectual background.

Copland's English translation is divided into sections on the work's introduction, the Manner of Kings, Health, the Four Seasons of the Year, Natural Heat, Food, Justice, Physiognomy, and Comportment.

It is particularly connected with the 13th-century English scholar Roger Bacon, who cited it more often than his contemporaries and even produced an edited manuscript with his own introduction and notes, an unusual honor.

[3] The Latin Secretum Secretorum was eventually translated into Czech, Russian, Croatian, Dutch, German, Icelandic, English, Aragonese,[4] Catalan,[5] Spanish, Portuguese, French, Italian, and Welsh.