The Art’s demonstrative ambitions explain some of the changes that Llull introduced into its successive versions. In this sense, the change in name assigned to the Art from the time of its first formulation (Ars compendiosa inveniendi veritatem) to that of its second (Ars demonstrativa), proves significant. The Ars demonstrativa seems to reflect, even in its very title, Llull’s desire to present his epistemological artifact as a science which could be harmonised with the Aristotelian scheme of the Posterior Analytics, that work of Aristotle’s which, according to scholastic tradition, dealt with ‘demonstrations’ and ‘necessary reasons’, in contrast to the ars inventiva or Dialectic, which dealt with probable reasons. This desire seems even more evident when one considers this new title of the Art in the light of another of the novelties offered by the Ars demonstrativa with respect to the Ars compendiosa inveniendi veritatem: Llull’s claim that his Art operated, not by mere ‘signs’ alone, but by means of three types of demonstration, demonstration ‘propter quid’ (by the cause), demonstration ‘quia’ (by the effect) and demonstration ‘per aequiparantiam’ (which, in his view, was the most demonstrative of all, even more so than demonstration ‘propter quid’ for which the scholastics, in keeping with Aristotle, reserved this privilege). Leaving aside this third type of demonstration, which Llull set forth as being of his own invention, the other two situate the Art in the same domain as the epistemological theorisations of the Posterior Analytics.
Llull’s Arts subsequent to the Ars demonstrativa never left this domain. On the contrary, the Illuminated Doctor attempted, in each one of them, progressively to deepen his desire, already present in this work, to re-consider the traditional relationship between ‘inventio’ and ‘demonstratio’. He thus aimed to eradicate, in line with the directives for science stipulated in the Posterior Analytics, the demonstrative deficiencies inherent to Dialectic, while simultaneously retaining the ‘inventive’ virtues characterising this latter discipline and which he had mechanised by means of his combinatorics. Paradoxically, this desire led Llull to create an Art at once demonstrative (like the sciences described in the Posterior Analytics) and universal (like Dialectic) that broke with the Aristotelian scientific model which admitted nothing but particular demonstrative sciences. This break with tradition turned Llull’s works into an unavoidable reference point for all those thinkers who, like Descartes or Leibniz, centuries later, wished to carry out similar enterprises.
Source: Josep M. Ruiz Simon, “ «Quomodo est haec ars inventiva?» (l’Art de Llull i la dialèctica escolàstica)”, Studia Lulliana, 33 (1993 ), pp. 97-98.
Llull was fully aware of the novelty of his epistemological project, and often insisted upon it. But it is a mistake to concentrate solely upon this novelty and to forget that the nature and significance of this Art and the meaning of the innovative elements it introduced cannot be interpreted without one’s keeping in mind the ‘old’ epistemology with respect to which it defined itself, namely that which his contemporaries claimed to follow to the letter. In this respect, one has to insist upon the fact that, by means of his Art, Llull explicitly proposed a method of argumentation which remained distinctive specifically on account of its differences from certain of the most characteristic features of the Aristotelian-scholastic theory of science. Llull’s was a method in which inventio and judicium did not follow parallel but rather, confluent paths, and which explicitly presented itself as a scientia universalis which, starting from the negation of the Aristotelian principle of the incommunicability of the principles of the sciences concerned with the distinct genera of being, broke with the similarly Aristotelian principle which, at the same time as imposing a science upon each genus, denied the possibility of demonstrating the principles of each science within a general discipline.
In short, in the 13th century, Llull proposed a way out from scholastic science which involved the omission of the two divisions by which it was defined: namely, that which existed between the pars inveniendi and the pars judicandi of logic, and that which existed between the different particular sciences. Subsequently, during the Renaissance and the 17th century, these two divisions were viewed as a peculiar drawback of scholasticism which impeded the advancement of knowledge.
Source: Josep Maria Ruiz Simon, L’Art de Ramon Llull i la teoria escolàstica de la ciència (Barcelona: Quaderns Crema, 1999), pp. 87-88.