ascertained, says M. Cousin, with unquestionable certainty, and for the
first time, from the examination of the Douay MS.; which alludes, in the
most precise terms, to the treatise on that subject. Hence the
importance of endeavouring to discover what has become of the MS.
Treatise of Moral Philosophy mentioned by Jebb, on the authority of Bale
and Pits, as it is very likely to have been the seventh part of the
_Opus Majus_. Jebb published the _Opus Majus_ from a Dublin MS.,
collated with other MSS.; but he gives no description of that MS., only
saying that it contained many other works attributed to Bacon, and in
such an order that they seemed to form but one and the same work. It
becomes necessary, therefore, to ascertain what were the different works
of Bacon included in the Dublin MS.; which is, in all probability, the
same mentioned as being in Trinity College, in the _Catalogi Codicum
Manuscriptorum Angliæ et Hiberniæ in unum Collecti_: Folio. Oxon, 1697.

According to this Catalogue, a Treatise on Moral Philosophy forms part
of Roger Bacon's MSS. there enumerated; and if so, why did Jebb suppress
it in his edition of the _Opus Majus_? Perhaps some of your
correspondents in Dublin may think it worth the trouble to endeavour to
clear up this difficulty, on which M. Cousin lays great stress; and
recommends, at the same time, a new and complete edition of the _Opus
Majus_ to the patriotism of some Oxford or Cambridge Savant. He might
well have included Dublin in his appeal for help in this undertaking;
which, he says, would throw a better light on that vast, and not very
intelligible monument of one of the most independent and greatest minds
of the Middle Ages.

J.M.
Oxford, April 9th.