century a young man like Bacon could hardly stand alone, and Bacon joined
the Franciscans, but before many years elapsed he embroiled himself with
his superiors. His friend, Grosseteste, died in 1253, the year after
Innocent IV issued the bull _Ad extirpanda_ establishing the
Inquisition, and Bacon felt the consequences. The general of his order,
Saint Bonaventura, withdrew him from Oxford where he was prominent, and
immured him in a Parisian convent, treating him rigorously, as Bacon
intimated to Pope Clement IV. There he remained, silenced, for some ten
years, until the election of Clement IV, in 1265. Bacon at once wrote to
Clement complaining of his imprisonment, and deploring to the pope the
plight into which scientific education had fallen. The pope replied
directing Bacon to explain his views in a treatise, but did not order his
release. In response Bacon composed the _Opus Majus_.

The _Opus Majus_ deals among other things with experimental science,
and in the introductory chapter to the sixth part Bacon stated the theory
of inductive thought quite as lucidly as did Francis Bacon three and a
half centuries later in the _Novum Organum_. [Footnote: Positis radicibus
sapientiae Latinorum penes Linguas et Mathematicam et Perspectivam, nunc
volo revolvere radices a parte Scientiae Experimentalis, quia sine
experientia nihil sufficienter scire protest. Duo enim simt modi
cognoscendi, scilicet per argumentum et experimentum. Argumentum concludit
et facit nos concedere conclusionem, sed non certificat neque removet
dubitationem ut quiescat animus in intuitu veritatis, nisi eam inveniat
via experientiae; quia multi habent argumenta ad scibilia, sed quia non
habent experientiam, negligunt ea, nee vitant nociva nex persequuntue
bona. J. H. Bridges, _The Opus Majus of Roger Bacon_ (Oxford, 1897), II,
167.]

Clement died in 1268. The papacy remained vacant for a couple of years,