Pope Gregory IX, who was eager to extirpate the remnant of the Albigensian heretics in Provence, root and branch, about this time established the permanent Inquisition (April, 1233), and appointed the violent Dominican friars as inquisitors, as the bishops, who had till then been entrusted with the persecution of the Albigenses, did not seem to him to treat the heretics with sufficient severity. In all the large towns of southern France where there were Dominican cloisters, in Montpellier among others, there were erected bloody tribunals, which condemned heretics or those suspected of heresy, and often quite innocent people, to life-long imprisonment or to the stake.

With these murderers, Rabbi Solomon, the upholder of the Talmud and of the literal interpretation of the Holy Writ, associated himself. He and his disciple Jonah said to the Dominicans: "You burn your heretics, persecute ours also. The majority of the Jews of Provence are perverted by the heretical writings of Maimuni. If you cause these writings to be publicly and solemnly burnt, your action will have the effect of frightening the Jews away from them." They also read dangerous passages from Maimuni's compositions to the inquisitors, at which the infatuated monks must have felt a shudder of holy horror. The Dominicans and Franciscans did not wait for a second invitation to interfere. The papal Cardinal-Legate, who was of the same fanatical zeal as Gregory IX, promptly took up the matter. The Dominicans may have feared that the fire of the Maimunist heresy might set their own houses ablaze. For the "Guide" had been translated by an unknown scholar into Latin during the first half of the thirteenth century. This translation was probably done in southern France, where Maimuni's philosophical composition had its second home, and where educated Jews were conversant with the Latin language. Maimuni might with justice appear to the guardians of Catholic orthodoxy to have deserved damnation for his religious philosophy. Thinking about religion in those days was looked upon in official Christendom as a capital sin. If the inquisitors had at that time possessed power over the persons of Jews, the Maimunists would have fared ill indeed; as it was, the persecution extended only to parchment. Maimuni's works, at least in Montpellier, were sought out in the Jewish houses, and publicly burnt. In Paris also, Maimuni's antagonists caused a fire to be kindled for the same purpose, and it is said to have been lit by a taper from the altar of one of the principal churches. The enemies of Judaism congratulated themselves that confusion now prevailed among the Jews, who till then had been united and compact, and thought that they were approaching their decay. The anti-Maimunists, however, were not yet satisfied. Confident in the support of those in power, they calumniated their opponents before the authorities, so that many members of the congregation of Montpellier were placed in great danger.

These proceedings naturally excited the horror of all the Jews on both sides of the Pyrenees. Solomon and his partisans were generally condemned. To invoke the aid of the temporal power, and moreover of a clergy which was swollen with hatred of the Jews, was, in the Jewish world, justly considered the most outrageous treachery; and to make the Dominicans judges of what was or was not consistent with Judaism, was to introduce the heathen enemy into the Holy of Holies. Samuel Saporta denounced this conduct in a letter to the French rabbis. Abraham ben Chasdaï of Barcelona, an enthusiastic admirer of Maimuni, who had censured Jehuda Alfachar for his insulting treatment of Kimchi, and for his espousal of the cause of Solomon, dispatched a letter denouncing Solomon's action in unmeasured terms, to the communities of Castile, Aragon, Navarre, and Leon. When Kimchi, who was in Burgos on his homeward journey, heard of this affair, he inquired of Alfachar, whether he still thought of keeping the informer and traitor, Solomon, under his protection. The intelligent followers of the latter, Nachmani and Meïr Abulafia, were deeply abashed, and remained silent. Public opinion condemned Solomon and the cause he represented. A poet of the Maimunist party composed on this occasion a very fine epigram:

"What thought ye to burn, when ye kindled the pyre
For writings more precious than gold?
Lo, truth is a flame—will ye quench it with fire?
In a chariot ablaze like the Tishbite of old,
It rises to Heaven. O, bigots, behold—
God's angel appears in the fire!"

By some secret power the system of informing in Montpellier through false witnesses, to which the adherents of Maimuni were exposed, was put an end to. More than ten of Solomon's partisans, who had been convicted of slander, were punished in the most cruel manner. Their tongues were cut out. But rarely does the gloom clear up in which these incidents are veiled. The fate of Solomon, the cause of all these events, is uncertain. The Maimunists observed with a certain malicious joy the severe punishment of their adversaries in Montpellier. A poet, probably Abraham ben Chasdaï, wrote an epigram upon it, which was soon in everyone's mouth:

"Against the guide of Truth,
A false pack raised their voices.
Punishment overtook them;
Their tongue was directed to heaven,
Now it lies in the dust."

With this tragic issue the struggle was still far from being at an end. The parties were more than ever embittered against each other.

When Abraham Maimuni learnt, with indignation, of the hostility towards his father, and the sad termination of the conflict which had broken out (January, 1235), he wrote a little book on the subject, entitled "War for God" (Milchamoth), in order to repel the attack upon the orthodoxy of his father, and to denounce the conduct of his opponents. This composition, directed, in the form of a letter, to Solomon ben Asher (in Lünel?), justified Maimuni's system on Maimuni's lines, and is valuable only on account of its historical data.

Solomon's effort to silence the free spirit of research in the province of religion was thus overthrown, and had met a lamentable end. Another French rabbi, of mild character and gentle piety, attempted another method of procedure, with greater success. Moses of Coucy, who, although of the Tossafist tendency, had held Maimuni in high esteem, undertook the task of fortifying the drooping spirit of religion among the Provençals and the Spaniards by delivering sermons and spirited exhortations. Moses was undoubtedly inspired in his attempt by the example of the preacher-monks, who aimed at overcoming the disbelief in the Roman Church by preaching in village after village, and who, to some extent, were successful. In the same manner the rabbi of Coucy traveled from one congregation to another in southern France and in Spain (1235), and was accordingly called the "preacher." But there was an important difference between the Jewish expounder of the law and the Catholic order of preachers. The one acted in genuine simplicity of heart, without any ambitious motives, with mildness on his lips and mildness in his heart. The Dominicans, on the other hand, put on their humility and poverty only for show, and behind them there lurked the devil of arrogance. They flattered their patrons in sermons, and humiliated their opponents unsparingly; they gained inheritances surreptitiously, and filled their cloisters with treasures; they nourished a bloody fanaticism, and strove after power and authority.