Charlatans discussed.
In the list of 232 titles are three works which all seem to bear on the same point and are perhaps different descriptions of one treatise, or else show that this was a favorite theme with Rasis. The idea in all three seems to be that no physician is perfect or can cure all diseases of all patients, that this is why many persons go to charlatans, and why sometimes quacks, old-wives, and popular practice succeed in certain cases where the most learned doctors have failed.[2700]
His interest in natural science.
Other titles show that Rasis was interested in natural science and not merely in the practice of medicine. Besides what would appear to have been a general treatise entitled, Opinions concerning Natural Things, he wrote on optics, holding that vision was not by rays sent forth from the eye, and discussing some of the figures in the work on optics ascribed to Euclid. In a letter he inquired into the reason for the creation of wild beasts and venomous reptiles; and in a third treatise wrote of the magnet’s attraction for iron and of vacuums.[2701] His interest in natural philosophy of a rather theoretical sort is indicated by an Explanation of the book of Plutarch or commentary on the book of Timaeus.[2702] Other titles attest his experimental tendency.[2703]
Rasis and alchemy.
Eight titles deal with alchemy[2704] and show that Rasis regarded transmutation as possible. One is a reply to Alkindi who held the opposite opinion.[2705] None of these writings seem to be extant in Arabic, however, and the Latin works of alchemy ascribed to Rasis are generally regarded as spurious. The thirteenth century encyclopedist, Vincent of Beauvais, made a number of citations from the treatise De salibus et aluminibus attributed to Rasis, but Berthelot[2706] regarded this work as later than Rasis and it is not found among our eight titles. The Lumen luminis, which is ascribed to Rasis[2707] and seems to have been translated by Michael Scot[2708] in the early thirteenth century, is also mainly devoted to these two substances, salts and alums. A Book of Seventy is ascribed to Rasis as well as to Geber. Berthelot was inclined to think that a Book of Secrets perhaps went back to Rasis. At least some good stories are told by Arabic chroniclers of Rasis’ connection with alchemy. One is to the effect that he abandoned the art as a result of a sound beating to which the caliph subjected him when he failed to transmute metals at order. Another states that in preparing the elixir he injured his eyes with its vapors and was cured by a physician who charged him a fee of five hundred dinars. Rasis paid the doctor’s bill, but, remarking that at last he had discovered the true alchemy and the best art of making gold, devoted the remainder of his life to the study and practice of medicine.[2709]
Titles suggestive of astrology and magic.
Rasis also wrote treatises on mathematics and the stars but it is not always easy to infer their contents from the titles which have alone reached us or to tell when mathematica means astrology. In one work he seems to have shown the excellence and utility of mathematica, but to have confuted those who extolled it beyond measure.[2710] In a letter he denied that the rising and setting of the sun and other planets was because of the earth’s motion and held that it was due to the movement of the celestial orb.[2711] In another letter he discussed the opinion of natural philosophers concerning the sciences of the stars and whether or not the stars were living beings.[2712] Rasis also discussed the difference between dreams from which the future can be forecast and other dreams.[2713] The title, Of exorcisms, fascinations, and incantations, under which, according to Negri’s Latin translation Rasis discussed the causes and cures of diseases by these methods and magic arts, should, in Ranking’s opinion, be more accurately translated as The Book of Divisions and Branches.[2714] A work On the Necessity of Prayer is also included in the list of 232 works ascribed to Rasis,[2715] while a Lapidary produced for Wenzel II of Bohemia (1278-1305) cites Rasis On the virtues of words and characters.[2716]
Conclusion.
Herewith we conclude our present survey of Arabian occult science especially in the ninth century, although in the following chapters we shall frequently encounter its influence. We have found the occult science closely associated with natural science and difficult to sever from it. In the authors and works reviewed we have found both scepticism and superstition, both rationalism and empiricism. But perhaps the most impressive point is that even superstition pretends to be or attempts to be scientific.