Rotating Letters as a Material Form of Thought
The works of the Majorcan philosopher and missionary Ramon Llull (1232–1316) are commonly and rightly regarded as foundational for the development of Western combinatorics and logic. Circular disks inscribed with the letters from B to K, which can be rotated in relation to each other, play a central role in his Ars Inveniendi Veritatem. A working model of the paper machine was included in several of his publications; a thread through the middle held the disks together.
Llull's motives are not easily understood today, but it seems safe to state that in his quest to convert the "infidels" to Christianity, the disk construction served theoretical functions as an encyclopaedia of religious thought, a tool to inspire meditation about its main topics, a way to generate new propositions, or even to abolish language altogether.
Several authors have pointed out that the model for Llull's disk was a divinatory device called a za'irjah, which was in use among the Muslims he was seeking to convert. The artefact offered a most astonishing function: Taking into account the moment in time of the enquiry, it generated a rhymed answer to any question posed. Possibly Llull was impressed by the fact that even kings placed a high trust in the procedure: "Many distinguished people have shown great interest in using [the za'irajah] for supernatural information, with the help of the well-known enigmatic operation that goes with it." (Ibn Khaldun)
Scrambling T-R-U-T-H. Rotating Letters as a Material Form of Thought, in: Variantology 4. On Deep Time Relations of Arts, Sciences and Technologies in the Arabic-Islamic World and Beyond, eds. Siegfried Zielinski and Eckhard Fuerlus (Cologne: König, 2010), pp. 215-266.
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