LIBER SEXTUS. 669 



speculis ex metallo non inscite assimilantur *, in quibus cernun- 

 tur utique imagines, sed non antequam expolita fuerint; sic 

 juvant demum regulae et praecepta, postquam exercitationis 

 limam subierint. Quod si tamen usque a principio regulse illne 

 fieri possint nitidae et quasi crystallinae, id optimum factu foret, 

 quandoquidem exercitatione assidua minus indigebunt. Atque 

 de Scientia Methodi (quam Prudentiam Traditivce nominavi- 

 mus) base dicta sint. 



Neque tamen illud praetermittendum, quod nonnulli viri 

 magis tumidi quam docti insudarunt circa Methodum quandam, 

 legitimae Methodi nomine baud dignam ; cum potius sit Me- 

 thodus imposturae ; quae tamen quibusdam ardelionibus acceptis- 

 sima proculdubio fuerit. Haec Metbodus ita scientiae alicujus 

 guttulas aspergit, ut quis sciolus specie nonnulla eruditionis 

 ad ostentationem possit abuti. Talis fuit Ars Lullii ; talis 

 Typocosmia a nonnullis exarata ; quae nihil aliud fuerunt quam 

 vocabulorum artis cujusque massa et acervuS ; ad hoc, ut qui 

 voces artis habeant in promptu, etiam artes ipsas perdidicisse 

 existimentur. Hujus generis collectanea officinam referunt 

 veteramentariam, ubi praesegmina multa reperiuntur, sed nihil 

 quod alicujus sit pretii. 2 



1 Assimulantur in the original. J. S. 



* The fundamental idea of Lully's art, and of all similar methods, may be thus 

 stated : The propositions which in the aggregate make up the sum of human know- 

 ledge consist of combinations of a certain number of conceptions. If then we had a 

 complete list of these conceptions so arranged as that all their admissible combinations 

 could be obtained by a mechanical process, such a list would be virtually equivalent 

 to a complete encyclopaedia. Even an incomplete list would give a certain portion, 

 greater or less according to circumstances, of all the knowledge which relates to the 

 conceptions which enter into it. It is obvious that such a method can give no criterion 

 of the truth of the propositions which it evolves ; but it may be so managed as that 

 every proposition shall be intelligible. To take a very simple instance : I confine my- 

 self to a table consisting of three columns, the first column to consist of names of 

 quadrupeds, as horse, stag, mouse, &c. ; the second of adjectives, such as large, small, 

 rare, &c. ; the third of names of classes of animals, as ruminant, rodent, and the like. 

 With a few more such columns Lully would have said that the natural history of 

 quadrupeds could be completely made out. Take any word from the iirst column, 

 any word from the second, any word from the third, and connect them by the logical 

 copula ; and if you are fortunate, you obtain a result as reasonable as this "a mouse 

 is a small rodent." But of course it might have appeared that a horse was a ru- 

 minant. 



Notwithstanding this obvious and incurable defect, different arrangements and modi- 

 fications of the art were proposed by many writers, some of whom probably believed 

 that it contained a key to all knowledge, while others believed that it would be at 

 least useful as a means of arranging and suggesting to the mind all that could be said 

 truly or falsely on a given subject. It appears to have suggested to Leibnitz one of 

 his early tracts, that on the art of combination, and thus to have led him to his notion 

 of reducing reasoning to a calculus. Analogous to Lully's art is a puerility which has 

 recently been revived, namely, mechanical verse-making. It seems also to have sug- 

 gested to Trithemius his method of secret writing, the fundamental idea of which may 

 be explained by saying that if there were six and twenty animals in the first column 

 of my table, the same number of adjectives in the second, and of classes in the third, 



