It is, however, with the Opus Majus that Bacon's real activity begins. It has been called by Whewell at once the Encyclopaedia and the Organum of the 13th century.
Part I. (pp. 1-22), which is sometimes designated De Utilitate Scientiarum, treats of the four offendicula, or causes of error. These are, authority, custom, the opinion of the unskilled many, and the concealment of real ignorance with pretence of knowledge. The last error is the most dangerous, and is, in a sense, the cause of all the others. The offendicula have sometimes been looked upon as an anticipation of Francis Bacon's Idola, but the two classifications have little in common. In the summary of this part, contained in the Opus Tertium, Bacon shows very clearly his perception of the unity of science and the necessity of encyclopaedic treatment.
Part II. (pp. 23-43) treats of the relation between philosophy and theology. All true wisdom is contained in the Scriptures, at least implicitly; and the true end of philosophy is to rise from the imperfect knowledge of created things to a knowledge of the Creator. Ancient philosophers, who had not the Scriptures, received direct illumination from God, and only thus can the brilliant results attained by them be accounted for.
Part III. (pp. 44-57) treats of the utility of grammar, and the necessity of a true linguistic science for the adequate comprehension either of the Scriptures or of books on philosophy.
2 The more important MSS. are: - (1) The extensive work on the fundamental notions of physics, called Communia Naturalium, which is found in the Mazarin library at Paris, in the British Museum, and in the Bodleian and University College libraries at Oxford; (2) on the fundamental notions of mathematics, De Cornmunibus Mathematicae, part of which is in the Sloane collection, part in the Bodleian; (3) Baconis Physica, contained among the additional MSS. in the British Museum; (4) the fragment called Quinta Pars Compendii Theologiae, in the British Museum; (5) the Compendium Studii Theologiae, in the British Museum; (6) the logical fragments, such as the Summulae Dialectices, in the Bodleian, and the glosses upon Aristotle's physics and metaphysics in the library at Amiens. See Little, The Grey Friars in Oxford (1892).
At the close of the Verb. Abbrev. is a curious note, concluding with the words, " ipse Rogerus fuit discipulus fratris Alberti!" The necessity of accurate acquaintance with any foreign language and of obtaining good texts, is a subject Bacon is never weary of descanting upon. A translator should know thoroughly the language he is translating from, the language into which he is translating, and the subject of which the book treats.
Part IV. (pp. 57-255) contains an elaborate treatise on mathematics, "the alphabet of philosophy," maintaining that all the sciences rest ultimately on mathematics, and progress only when their facts can be subsumed under mathematical principles. This fruitful thought he illustrates by showing how geometry is applied to the action of natural bodies, and demonstrating by geometrical figures certain laws of physical forces. He also shows how his method may be used to determine some curious and long-discussed problems, such as the light of the stars, the ebb and flow of the tide, the motion of the balance. He then proceeds to adduce elaborate and sometimes slightly grotesque reasons tending to prove that mathematical knowledge is essential in theology, and closes this section of his work with two comprehensive sketches of geography and astronomy. That on geography is particularly good, and is interesting as having been read by Columbus, who lighted on it in Petrus de Alliaco's Imago Mundi, and was strongly influenced by its reasoning.
Part.V. (pp. 256-357) treats of perspective. This was the part of his work on which Bacon most prided himself, and in it, we may add, he seems to owe most to the Arab writers Kindi and Alhazen. The treatise opens with an able sketch of psychology, founded upon, but in some important respects varying from, Aristotle's De Anima. The anatomy of the eye is next described; this is done well and evidently at first hand, though the functions of the parts are not given with complete accuracy. Many other points of physiological optics are touched on, in general erroneously.
Continued on page four.
This article is from the 1911 edition of an encyclopedia, which is out of copyright here in the U.S. See the encyclopedia main page for disclaimer and copyright information.

