Part VI. (pp. 445-477) treats of experimental science, domina omnium scientiarum. There are two methods of knowledge: the one by argument, the other by experience. Mere argument is never sufficient; it may decide a question, but gives no satisfaction or certainty to the mind, which can only be convinced by immediate inspection or intuition. Now this is what experience gives. But experience is of two sorts, external and internal; the first is that usually called experiment, but it can give no complete knowledge even of corporeal things, much less of spiritual. On the other hand, in inner experience the mind is illuminated by the divine truth, and of this supernatural enlightenment there are seven grades.
Experimental science, which in the Opus Tertium (p. 46) is distinguished from the speculative sciences and the operative arts in a way that forcibly reminds us of Francis Bacon, is said to have three great prerogatives over all other sciences: - (1) It verifies their conclusions by direct experiment; (2) It discovers truths which they could never reach; (3) It investigates the secrets of nature, and opens to us a knowledge of past and future. As an instance of his method, Bacon gives an investigation into the nature and cause of the rainbow, which is really a very fine specimen of inductive research.
The seventh part of the Opus Majus (De Morali Philosophia), not given in Jebb's edition, is noticed at considerable length in the Opus Tertium (cap. xiv.). Extracts from it are given by Charles (pp. 339-348).
As has been seen, Bacon had no sooner finished this elaborate work than he began to prepare a summary to be sent along with it. Of this summary, or Opus Minus, part has come down and is published in Brewer's Op. Ined. (313-389) , from what appears to be the only MS. The work was intended to contain an abstract of the Opus Majus, an account of the principal vices of theology, and treatises on speculative and practical alchemy. At the same time, or immediately after, Bacon began a third work as a preamble to the other two, giving their general scope and aim, but supplementing them in many points. The part of this work, generally called Opus Tertium, is printed by Brewer (pp. 1-310), who considers it to be a complete treatise. Charles, however, has given good grounds for supposing that it is merely a preface, and that the work went on to discuss grammar, logic (which Bacon thought of little service, as reasoning was innate), mathematics, general physics, metaphysics and moral philosophy. He founds his argument mainly on passages in the Communia Naturalium, which indeed prove distinctly that it was sent to Clement, and cannot, therefore, form part of the Compendium, as Brewer seems to think. It must be confessed, however, chat nothing can well be more confusing than the references in Bacon's works, and it seems well-nigh hopeless to attempt a complete arrangement of them until the texts have been collated and carefully printed.
All these large works Bacon appears to have looked on as preliminaries, introductions, leading to a great work which should embrace the principles of all the sciences. This great work, which is perhaps the frequently-referred-to Liber Sex Scientiarum, he began, and a few fragments still indicate its outline.
Continued on page five.
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