essentials of the great branches of true knowledge. The work has well been designated 'at once the Encyclopædia and the Organon of the thirteenth century.' It is animated by the fresh breath of original study of nature; and though, as was inevitable, the fundamental ideas are in many respects those of the time, the mode of handling and applying them is wonderfully free from the battling restraints that meet one in scholastic speculations. The 'Opus Majus' itself professed to be no more than an encyclopædic outline, and only touched the main features of the great sciences, grammar and logic, mathematics, physics (of which perspective, i.e. optics, was for Bacon the type), experimental research, moral philosophy; it was left to other works to give a more detailed treatment of the various branches.
Later investigations have succeeded in disclosing various interesting and important fragments of the detailed work to which Bacon seems to have applied himself on the completion of the 'Opus Majus.' It is not possible to give an exhaustive enumeration of the extant manuscripts. Those known to exist, and partially examined, are very numerous and in every variety of condition; there are doubtless others not yet brought to light. It is hardly possible, moreover, so to connect the known manuscripts with the indications which can be gathered of Bacon's projected or accomplished writings as to effect some partial classification of them. Either Bacon himself or the transcribers of the manuscripts must have been in the habit of incorporating an accomplished writing in anew work, with such changes of beginning and ending as to bring about the junction; and as the titles of the existing manuscripts generally follow some of the introductory sentences, it is not uncommon to find that writings cited under various titles and assigned to various works are in substance identical. It will be best here to state what has been determined regarding Bacon's activity as a writer after the composition of the 'Opus Majus,' and to point out what manuscripts exist of the products of his activity.
The older authorities agreed in asserting that the 'Opus Majus' was not the only writing prepared by Bacon at the request of Clement, but their accounts of the other treatises were confused and imperfect. Wood quotes from the writing now called 'Opus Tertium,' but regards it as part of a writing called 'Opus Minus' (Brewer, pref. p. 98, says of the passage quoted: 'This passage does not occur in the Digby MS., therefore Wood must have seen some other copy of the "Opus Minus" not now discoverable.' But this is an error. The passage is given in Brewer's own reprint of the 'Opus Tertium,' pp. 272-3, and the title of the manuscript is not 'In Opere Minore,' but merely 'In Opere suo'). Jebb, who had carefully consulted the manuscripts in the British Museum, came upon traces of two writings, called 'Opus Minus' and 'Opus Tertium, but did not succeed in obtaining clear insight into their nature and scope. In 1848, however, Cousin discovered in the public library at Douai an important manuscript, of which he gave a full abstract in the 'Journal des Savants' of the same year. Other manuscripts of this work exist, and it has since been printed by Brewer under the undoubtedly correct title of 'Opus Tertium.' The biographical details given in the seventy-five chapters of printed text are of the utmost value, and the references to other writings enable a clear idea to be formed of the 'Opus Minus,' and a partial idea to be formed of certain projected treatises. From what Bacon himself says it becomes clear (1) that Jebb's edition of the 'Opus Majus' is imperfect as regards pt. ii., on grammar; is wanting in pt. vii., on moral philosophy; and is redundant by inclusion of a long treatise 'de multiplicatione specierum,' which is either part of a later work or an independent tract; (2) that the work called 'Opus Minus,' sent to Clement soon after the 'Opus Majus,' contained (a) a brief view of the contents of the larger treatise, (b) a criticism of the errors of theological study, and (c) a detailed treatment of speculative and practical alchemy. Only one manuscript (that in the Bodleian, Digby, 218) has been discovered which corresponds to the description of the 'Opus Minus.' It is in very imperfect condition, but the fragments, printed in Brewer's valuable edition, seem to represent all that we are likely to find of the work. Jebb, misinterpreting some references in the manuscripts before him, had conjectured that the 'Opus Minus' was intended to contain a body of separate treatments of the various sciences. This is incorrect, but it is certain that Bacon projected such separate treatments, and intended to send them to Clement. The chapters printed as the 'Opus Tertium' contain many forward references, and by comparing these with link-words found in the recently disclosed manuscripts M. Charles has endeavoured to reconstruct the plan of Bacon's work and to determine the manuscript fragments of it. From the circumstance above mentioned, however, it is very difficult to effect this satisfactorily, and it seems highly improbable that Bacon was able to prepare detailed treatises, following up the introduction called
