PREFACE.

Moreover, chapters of this kind, collected into one work, inscribed On the Secret Works of Art and Nature and the Nullity of Magic, were often printed in the form of a letter given to William, Bishop of Paris. But since Bacon himself w expressly calls Chapter VII the Book on the Accidents of Old Age, and chapters 10 and 11 were written at different times—x namely the years 602 and 603 of the Arabs These dates correspond to approximately 1205–1207 AD in the Gregorian calendar, though the text uses them to show the work was composed over time.—it is established for certain that this work is not a single letter, but composed of several parts. To this, if I am not mistaken, are to be referred the treatises: On the Marvelous Power of Art and Nature, On the Vigor of Art and Nature, On the Hidden Works of Nature, On Works Not Hidden, On the Marvelous Things, Against the Necromancers, On Necromantic Images, On Geomancy, On Incantations, On the Practices of Magic, and On the Prolongation of Life; so much so that those eleven books numbered by biographers barely contain as many pages.

Therefore, the first work of Bacon which grew into a proper volume was the Opus Majus original: "Opus Majus"; usually translated as "The Greater Work." dedicated to Clement Pope Clement IV., which we now bring to light. To this work, distributed into six parts, he added books on Prognostications from the Stars and on the Multiplication of Species In Bacon’s physics, the "multiplication of species" refers to the way force or light propagates through a medium., and joined a treatise on Moral Philosophy at the end. But these parts, when they were transcribed separately and each adorned with its own and diverse titles, were held to be entire books and increased the catalogs of biographers. Hence, the first and second parts present to us the books On the Impediments of Wisdom, On the Causes of Human Ignorance, and On the Utility of the Sciences; the third, the book On the Utility of Languages; the fourth, On the Centers of Weights, On Weights, On the Value of Music, On the Judgments of Astrology, On Cosmography, On the Situation of the World, On the Regions of the World, On the Situation of Palestine, On Sacred Places, and descriptions of the world’s locations; to which is also attached an astrological treatise containing a book On the Utility of Astronomy, prognostications from the course of the stars, and perhaps a small work On the Aspects of the Moon. The fifth part is multiplied into a certain Singular Perspective, Distinct Perspective, and Continuous Perspective In this context, "Perspective" refers to the science of optics.; and the work that follows encompasses in itself all the books that deal with the Multiplication of Species. To the sixth part, however, seem to belong the treatises On Experimental Science, On Solar Rays, and On Colors to be Made by Art.

w Opus Majus, page 469.
x See The Chemical Theater, Volume 5, pages 960, 961.