Opus Majus of Roger Bacon, Vol. I (Bridges ed.)

operations with which moral or political science is concerned. This science is the mistress of every department of philosophy. It employs and controls them for the advantage of states and kingdoms. It directs the choice of men who are to study in sciences and arts for the common good. It orders all members of the state or kingdom so that none shall remain without his proper work.’

The seventh part of the Opus Majus is for the first time printed in this edition. Unfortunately it is not complete. It consisted, as we learn from the fourteenth chapter of the Opus Tertium, of six divisions; and the only two MSS. manuscripts of it as yet discovered, those of Dublin and Oxford (the first of which, as will be shown afterwards, is copied from the second), stop short before the conclusion of the fourth. We gather, however, that the missing portions are not of primary importance.

Another alteration of considerable importance has been made in the present edition. Professor Émile Charles, in his very important monograph on Roger Bacon (Bordeaux, 1861), pointed out that the treatise De Multiplicatione Specierum On the Multiplication of Species/Radiant Forces, which in Jebb's edition of the Opus Majus is placed between the fifth and sixth sections of the work, does not in reality belong to it. And indeed the second sentence of the treatise makes this evident. ‘Recolendum est,’ Bacon observes, ‘quod in tertia parte hujus operis tactum est quod essentia, substantia, natura, potestas, potentia, virtus, vis, significant eandem rem.’ original: "It must be remembered that in the third part of this work it was touched upon that essence, substance, nature, power, potentiality, virtue, and force signify the same thing." No such passage is to be found in any part of the Opus Majus, least of all in the third part, which deals with Comparative Philology. Here again the Opus Tertium comes to our aid. Several references will be found there to a distinct treatise sent to Pope Clement IV simultaneously with the Opus