xix

INTRODUCTION

...of nature.¹ original: "naturae" There is nothing about these things in the Greater Work original: "Opus Majus", as we have it. The probable inference is that Bacon is still referring to the Lesser Work original: "Opus Minus", which in that case would have incorporated parts of the Letter on the Secret Works of Nature original: "Epistola de secretis operibus naturae" or On the Marvelous Power of Art and Nature original: "De mirabili potestate artis et naturae". This view receives support from Chapter XXVI of the Third Work original: "Opus Tertium" (edited by Brewer, page 99): "But in the Lesser Work where I treated the celestial bodies, I explained those things more fully, where I touched upon the greatest secrets of nature, which ought not to be explained to everyone, but only to the wisest men." original Latin: "Sed in Opere Minore ubi de coelestibus tractavi, exposui magis ista, ubi maxima secreta naturae tetigi, quae non sunt cuilibet exponenda, sed solis sapientissimis viris."

Among the most interesting passages of the new fragment is that in which Bacon defends, and urges the Pope to regulate, the study of magic (pages 17 through 18).

The remainder of the treatise here printed corresponds in the main, apart from certain exceptions which will be noted presently, with the fragment edited by Professor Duhem.

The Optics original title: "Perspectiva" follows closely the order of subjects adopted in Part V of the Greater Work original: "Opus Majus", but there is evidence that the sections into which Part V was then divided did not correspond to the parts and distinctions found in Bridges' edition. In the Third Work original: "Opus Tertium" (page 24 below) Bacon says: "And I verify both these things and all things connected to them in three distinctions with their chapters. Then in the fourth, fifth, and sixth distinction I proceed to the further reaches of this science, and first I declare those things which are required for vision." original Latin: "Et hec et omnia eis annexa verifico in tribus distinctionibus cum capitulis suis. Deinde in 4ª, 5ª et 6ª distinctione procedo ad ulteriora istius scientie, et primo declaro que exiguntur ad visum." A distinction was a standard method of dividing a subject in medieval academic texts. The "fourth distinction" certainly corresponds to Distinction 8 of Part I in the Optics as we have it; and probably Distinctions 5 and 6 corresponded to Distinctions 9 and 10, while Distinctions 1, 2, and 3 corresponded to Distinctions 1 through 7. It seems therefore that in a later revision of the Greater Work, a different division of the material was adopted either by Bacon himself or by an editor.

In the section On Experimental Science original: "De Scientia Experimentorum" the earlier chapters of Part VI of the Greater Work are summarized in a single page. The sub-section On the Fifth Essence² original: "De quinta essentia" corresponds generally to pages 215 through 222 of the Greater Work, but contains some...

¹ Compare page 532 and following in Brewer's edition.
² I suspect that On the Fifth Essence original: "De quinta essentia." The fifth essence, or quintessence, was the material believed to compose the celestial bodies, being purer than the four earthly elements. was originally a marginal note referring to the preceding sentences, not a heading to a new chapter.