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An interesting thread for historians to follow is how and where Llull
got his own pioneering notions. For some of them we have a hint.
Thus, the idea of starting from a finite set of rules to develop a
whole system has a remote ancestor in Euclides and the Alexandrian
greeks and a more recent and innovative version in Al-Khwarizmi's
"algebra" work -that Llull quotes as a source. This book,
translated into Latin shortly before Llull's time, created a
sensation with its novel idea of rule-directed manipulations and
prescribed "algorithms" (a concept and a word derived from the muslim
mathematician). On the other hand, Llull's idea of a comprehensive
method to encompass such rules and develop concepts was probably a
formal extension of a now-forgotten integral part of medieval
education: the complex set of elaborated techniques for reminding and
structucturing things in human memory in a printless age (actually,
Llull's method was developed in this sense by Petrus Ramus in the
l6th century and was then an inspiration for Bacon and Descartes).
As for the mechanical devices (the rotating disks), we now know that
similar "question-answering disks" were on sale in the 1260's or
1270's in Algeria (as tools for divination), and that Llull
could well know them before his 1274 formulation. (Llull's disks
met an unexpected use in cryptography, when Leopardi first used them
for coding, and we can still recognize them in the rotors of the WW
II German Enigma machine, a distant echo of Llull's disks.)
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