The Ars demonstrativa was the second version of the
Lullian Ars, and revised and completed the Ars
compendiosa inveniendi veritatem (1274). It was composed in
Montpellier in 1283. The work is accompanied by Figures and an
Alphabet; the former are graphic symbols which make the structural
components of the Ars visible and facilitate the operation
of the combinatorial mechanisms and the calculations. As regards
the Alphabet, the letters A S T V X Y and Z represent the Figures
mentioned above, while the others – namely those between B
and R – serve to designate the concepts contained within
Figure S, the figure pertaining to the rational soul.
The Ars demonstrativa has four parts or
‘distinctions’, of which the final part is a list of
questions relating to the preceding parts, accompanied by their
corresponding solutions in symbolic notation. The first distinction
gives a detailed description of the figures. The second distinction
expounds the ‘conditions’ of the Ars, the
mechanisms which enable the reader to obtain information on the
basis of the principles from Figures A V X, with a view to
discovering the truth or falsity – Figures Y Z – by
using Figures T and S, which establish relationships between the
principles. The third distinction offers sixteen modes, or rather,
applications for the mechanisms of the Ars, which are:
remembering, understanding, loving, believing, contemplating,
finding, ordering, preaching, expounding, resolving, judging,
showing, disputing, advising, accustoming, curing.