the eleventh-century mind had been as rigid as the Roman mind of the first century, mediæval civilization could hardly, after the collapse of the crusades, have failed to degenerate as Roman civilization degenerated after the defeat of Varus. Being more elastic, it began, under an increased tension, to develop new phases of thought. The effort was indeed prodigious and the absolute movement possibly slow, but a change of intellectual attitude may be detected almost contemporaneously with the fall of the Latin kingdom in Palestine. It is doubtless true that the thirteenth century was the century in which imaginative thought reached its highest brilliancy, when Albertus Magnus and Saint Thomas Aquinas taught, when Saint Francis and Saint Clara lived, and when Thomas of Celano wrote the Dies Iræ. It was then that Gothic architecture touched its climax in the cathedrals of Chartres and Amiens, of Bourges and of Paris; it was then also that Blanche of Castile ruled in France and that Saint Louis bought the crown of thorns, but it is equally true that the death of Saint Louis occurred in 1270, shortly after the thorough organization of the Inquisition by Innocent IV in 1252, and within two years or so of the production by Roger Bacon of his Opus Majus.

      The establishment of the Inquisition is decisive, because it proves that sceptical thought had been spread far enough to goad the Church to general and systematic repression, while the Opus Majus is a scientific exposition of the method by which the sceptical mind is trained.

      Roger Bacon was born about 1214, and going early to Oxford fell under the influence of the most liberal teachers in Europe, at whose head stood Robert Grosseteste, afterward Bishop of Lincoln. Bacon conceived a veneration for Grosseteste, and even for Adam de Marisco his disciple, and turning toward mathematics rather than toward metaphysics he eagerly applied himself, when he went to Paris, to astrology and alchemy, which were the progenitors of the modern exact sciences. In the thirteenth 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, but in 1271 Gregory X came in on a conservative reaction. Bacon passed most of the rest of his life in prison, perhaps through his own ungovernable temper, and ostensibly his writings seem to have had little or no effect on his contemporaries, yet it is certain that he was not an isolated specimen of a type of intelligence which suddenly bloomed during the Reformation. Bacon constantly spoke of his friends, but his friends evidently did not share his temperament. The scientific man has seldom relished martyrdom, and Galileo’s experience as late as 1633 shows what risks men of science ran who even indirectly attacked the vested interests of the Church. After the middle of the thirteenth century the danger was real enough to account for any degree of secretiveness, and a striking case of this timidity is related by Bacon himself. No one knows even the name of the man to whom Bacon referred as “Master Peter,” but according to Bacon, “Master Peter” was the greatest and most original genius of the age, only he shunned publicity. The “Dominus experimentorum,” as Bacon called him, lived in a safe retreat and devoted himself to mathematics, chemistry, and the mechanical arts with such success that, Bacon insisted, he could by his inventions have aided Saint Louis in his crusade more than his whole army. [Footnote: Émile Charles, Roger Bacon. Sa vie et ses ouvrages, 17.] Nor is this assertion altogether fantastic. Bacon understood the formula for gunpowder, and if Saint Louis had been provided with even a poor explosive he might have taken Cairo; not to speak of the terror which Greek fire always inspired. Saint Louis met his decisive defeat in a naval battle fought in 1250, for the command of the Nile, by which he drew supplies from Damietta, and he met it, according to Matthew Paris, because his ships could not withstand Greek fire. Gunpowder, even in a very simple form, might have changed the fate of the war.

      Scepticism touching the value of relics as a means for controlling nature was an effect of experiment, and, logically enough, scepticism advanced fastest among certain ecclesiastics who dealt in relics. For example, in 1248 Saint Louis undertook to invade Egypt in defence of the cross. Possibly Saint Louis may have been affected by economic considerations also touching the eastern trade, but his ostensible object was a crusade. The risk was very great, the cost enormous, and the responsibility the king assumed of the most serious kind. Nothing that he could do was left undone to ensure success. In 1249 he captured Damietta, and then stood in need of every pound of money and of every man that Christendom could raise; yet at this crisis the Church thought chiefly of making what it could in cash out of the war, the inference being that the hierarchy suspected that even if Saint Louis prevailed and occupied Jerusalem, little would be gained from an ecclesiastical standpoint. At all events, Matthew Paris has left an account, in his chronicle of the year 1249, of how the pope and the Franciscans preached this crusade, which is one of the most suggestive passages in thirteenth-century literature:

      “About the same time, by command of the pope, whom they obeyed implicitly, the Preacher and Minorite brethren diligently employed themselves in preaching; and to increase the devotion of the Christians, they went with great solemnity to the places where their preaching was previously indicated, and granted many days of indulgence to those who came to hear them.... Preaching on behalf of the cross, they bestowed that symbol on people of every age, sex and rank, whatever their property or worth, and even on sick men and women, and those who were deprived of strength by sickness or old age; and on the next day, or even directly afterwards, receiving it back from them, they absolved them from their vow of pilgrimage, for whatever sum they could obtain for the favour. What seemed unsuitable and absurd was, that not many days afterwards, Earl Richard collected all this money in his treasury, by the agency of Master Bernard, an Italian clerk, who gathered in the fruit; whereby no slight scandal arose in the Church of God, and amongst the people in general, and the devotion of the faithful evidently cooled.” [Footnote: Matthew Paris, English History, translated by the Rev. J. A, Giles, II, 309.]

      When the unfortunate Baldwin II became Emperor of the East in 1237, the relics of the passion were his best asset. In 1238, while Baldwin was in France trying to obtain aid, the French barons who carried on the government at Constantinople in his absence were obliged to pledge the crown of thorns to an Italian syndicate for 13,134 perpera, which Gibbon conjectures to have been besants. Baldwin was notified of the pledge and urged to arrange for its redemption. He met with no difficulty. He confidently addressed himself to Saint Louis and Queen Blanche, and “Although the king felt keen displeasure at the deplorable condition of Constantinople, he was well pleased, nevertheless, with the opportunity of adorning France with the richest and most precious treasure in all Christendom.” More especially with “a relic, and a sacred object which was not on the commercial market.” [Footnote: Du Cange, Histoire de L’empire de Constantinople sous les empereurs Français, edition de Buchon, I, 259.]

      Louis, beside paying the loan and the cost of transportation which came to two thousand French pounds (the mark being then coined into £2, 15 sous and 6 pence), made Baldwin a present of ten thousand pounds for acting