Faith-Based Logic Machine

Raymond Lull, a 13th century Christian Theologian, sought to convince others with similar faith foundations (Jews, Muslims) that eternal truths can be found in accepting Jesus of Nazareth as their savior. To aid his efforts, Mr. Lull created a system in which subjects and predicates of certain theological propositions were arranged in different geometrical figures -- he would use this system to catch those he sought to convince in logical inconsistincies. Despite being promptly banished (suprisingly not burned at the stake) from a number of cities for what many percieved to be an obvious disturbance of their respective faith communities, he carried on with his mission:

Lull started from the position of respect for those he sought to convince. He knew that both Muslims and Jews were capable of exalted ethical lives and profound spiritual experience, and he freely borrowed from them lines of reasoning, stories and parables, and even terminology. Like Francis, he would not blind himself with Christian dogma, nor did he fail for a moment to discern the dissolute condition of much of Christendom. Nevertheless, he felt that all peoples should accept the special doctrines of the Trinity and the Incarnation. Historians and scholars shy away from dealing with the apparent paradox of an encompassing tolerance conjoined with doctrinal conviction. Given Lull's frequent criticism of church politics and priestly abuses, one might suspect that within the limited framework of theological language, Lull wished to demonstrate universal doctrines, especially that Deity manifests through creative triads whilst remaining wholly transcendent, and that manifest Deity directly enters the world to awaken human beings to their spiritual possibilities. Lull's sense of the Divine is intimate and yet not personal in any anthropomorphic sense. The Dignities, which he varies from time to time, are in general Bonitas (goodness), Magnitudo (greatness), Eternitas (eternity), Potestas (power), Sapientia (wisdom), Voluntas (will), Virtus (virtue), Veritas (truth) and Gloria (glory). Whilst his Ars Magna – Great Art – is the art of demonstration at the level of intellectus, a way of finding truth, it is at the level of voluntas a way of training the will to love Truth, and at the level of memoria it is an art of memory.

At first, Lull hoped the Dominicans would adopt his art of memory, but they rejected it in favour of their own. Their art, drawn from the rhetorical tradition, concerned itself with architectural metaphors. A theatre could be constructed in such a way that its internal geometry and embellishments could be used to 'store' arguments and conclusions for a speaker in a debate. As he disputed doctrines and theses, his eye could pick up from the construction of the building the points he had associated with it. This art helped a speaker remember his argument. Lull's art was of a wholly different order. The Dignities were to be meditated upon until one saw clearly their nature and meaning. The symbolic permutations of the Dignities and relative predicates would help one recollect eternal truths and their applications. If the rhetorical art was an art of memory, Lull's art was a mode of Platonic recollection. The Franciscans welcomed this art, as did Pico della Mirandola, Nicholas of Cusa and Giordano Bruno during the Italian Renaissance.

This guy was way ahead of his time. Though I generally disagree with exclusive adherence to any religious institution, Mr. Lull sought an atmosphere of interfaith dialogue and tolerance -- and he did so with intentions of being reasonable (unlike Pope Urban II, who promoted the first crusade to kill heathenous Turks a little over one-hundred years earlier).

And yes, 'faith-based logic' does seem a bit oxymoronic.
Tip to LaputanLogic for the links.