Thoughtful Jews were not slow to recognize their bitterest foe in this new-Christian, and they prepared for a severe struggle with him, notwithstanding that their choice of weapons was limited. Christians were not only free to say what they pleased in demonstration and defense of their doctrines, but could appeal to the summary authority of the sword and the dungeon. Jews were forced to all kinds of circumlocution and ambiguity to avoid provoking the violence of their adversaries. The gallant stand of a mere handful of Jews against power and arrogance should excite the admiration of all whose sympathies are not with victorious tyranny, but with struggling right.
The campaign against Paul de Santa Maria was opened by a young man, Joshua ben Joseph Ibn-Vives of Lorca (Allorqui), a physician and an Arabic scholar, who had formerly sat at the feet of the renegade rabbi. In an humble epistle, as though a docile pupil were addressing an illustrious master, Joshua Allorqui administered many a delicate reproof to his apostate teacher, and at the same time, by his naïve doubts, dealt destructive blows at the fundamental doctrines of Christianity. He observes in his introduction that the conversion of his beloved teacher had to him more than to others been a source of astonishment and reflection, as his example had been a main support of his own religious belief. He was at a loss to conceive the motives of the sudden change. He could not think that he had been led away by desire for worldly distinction, "for I well remember," he says, "how, surrounded by riches and attendants, thou didst yearn for thy former humble state with its life of retirement and study, and how it was thy wont to speak of thy high position as empty mockery of happiness." Nor could he suppose that Paul's Jewish convictions had been disturbed by philosophic doubt, as up to the moment of his baptism he had conscientiously observed all the ceremonial laws, and had known how to discriminate between the kernel of philosophic truth which harmonizes with religion and the pernicious shell which so often passes for the real teaching. Could it be that the sanguinary persecution of the Jews had led him to doubt the possibility of the enduring power of Judaism? But even this theory was untenable, for Paul could not be unaware of the fact that only a minority of Jews live under Christian rule, that the larger numbers sojourn in Asia, and enjoy a certain degree of independence; so that if it pleased God to allow the communities in Christian lands to be extirpated, the Jewish race would not by any means disappear from the face of the earth. There remained, continued Joshua Vives of Lorca, the assumption that Paul had carefully studied Christianity, and had come to the conclusion that its dogmas were well founded. He begged him, therefore, to impart to him the convictions at which he had arrived, and thus dissipate the doubts which he (Joshua) still entertained as to the truth of Christianity. Allorqui then detailed the nature of his doubts, covertly but forcibly attacking the Christian system. Every sentence in this epistle was calculated to cut the Jew-hating new-Christian to the quick. The evasive and embarrassed reply, which Paul indited later on, clearly indicated how he had winced under this attack.
The philosopher, Chasdaï Crescas, also came forward in gallant defense of the religion of his fathers. He composed (1396) a polemical treatise (Tratado), in which he tested philosophically the Christian articles of faith, and demonstrated their untenableness. This work was addressed to Christians more than to Jews, and was particularly intended for the perusal of Spaniards of high rank whose friendship Chasdaï Crescas enjoyed. Hence it was written not in Hebrew but in Spanish, which the author employed with ease, and its tone was calm and moderate. Chasdaï Crescas set forth the unintelligibility of the doctrines of the Fall, the Redemption, the Trinity, the Incarnation, the Immaculate Conception, and Transubstantiation, and examined the value of baptism, the coming of Jesus, and the relation of the New Testament to the Old, with dispassionate deliberation, as if he did not know that he was dealing with questions which might at any moment light the fires of an auto-da-fé.
At about the same time an accomplished Marrano, who had relapsed into Judaism, published a pungent attack on Christianity and the new-Christians. In the entire history of Judæo-Christian controversy no such stinging satire had been produced on the Jewish side as that now issued by the physician, astronomer, historical student, and grammarian Profiat Duran. During the bloody persecution of 1391 in Catalonia, Profiat Duran, otherwise Isaac ben Moses, or, as he called himself in his works, Efodi (Ephodæus), had been forced to simulate conversion to Christianity. He was joined by his friend David Bonet Buen-Giorno. Both resolved at a convenient opportunity to abandon their hated mask and emigrate to Palestine, where they could freely acknowledge Judaism. Their affairs being arranged, Profiat Duran traveled to a seaport town in the south of France, and there awaited his friend. The latter, in the meantime, was sought out by or came across the Jew-hating apostate, Solomon Paul de Santa Maria, and was prevailed upon to remain a Christian. What was Profiat Duran's astonishment when he received a letter announcing, with much exultant vaporing, the definite acknowledgment of Christianity by En Bonet, who exhorted him also to remain in the pale of his adopted faith. The letter contained an enthusiastic panegyric of Paul de Santa Maria, who had been taken into the favor of the king of Castile. Profiat Duran could not remain silent. In reply, he inflicted punishment on his friend, and more particularly on the proselytizing Paul, in an epistle characterized by the keenest irony, which has not yet lost its sting. It pretends to assent to everything advanced by Bonet, and to confirm him in his resolve to remain a Christian. "Be not ye like your fathers" (Altehi ka-Abothecha) is the refrain throughout, and so artfully is this admonition employed that Christians used it (under the title Alteca Boteca) as an apology for Christianity. Whilst thus pretending to criticise the errors of the older faith, Profiat Duran dwells on the Christian dogmas, naïvely describing them in their most reprehensible form. He concentrates on the weaknesses of Christianity the full light of reason, Scriptural teaching and philosophic deduction, apparently with no desire to change his friend's intention. A portion of the satire is directed against the Jew-hater Paul de Santa Maria, upon whom Bonet had bestowed unstinted praise. "Thou art of opinion that he may succeed in becoming pope, but thou dost not inform me whether he will go to Rome, or remain at Avignon"—a cutting reference to the papal schism distracting the church. "Thou extollest him for having made efforts to free Jewish women and children from the obligation of wearing the Jew badge. Take the glad tidings to the women and children. For myself, I have been told that he preached mischief against the Jews, and that the cardinal of Pampeluna was compelled to order him to be silent. Thou art of opinion that he, thy teacher, will soon receive the miter or a cardinal's hat. Rejoice, for then thou also must acquire honors, and wilt become a priest or a Levite." Towards the end Profiat Duran changes irony into a tone of seriousness: he prays his former friend not to bear as a Christian the name of his respected father who, had he been alive, would sooner have had no son than one faithless to his religion. As it is, his soul in Paradise will bewail the faithlessness of his son. This satirical epistle was circulated as a pamphlet. Its author sent copies not only to his former friend, but also to the physician of the king of Castile, the chief rabbi, Don Meïr Alguades. So telling was the effect produced, that the clergy, as soon as they discovered its satirical character, made it the subject of judicial inquiry, and committed it to the flames. At the request of Chasdaï Crescas, Profiat Duran wrote another anti-Christian work, not, however, a satire, but in the grave language of historical investigation. In this essay he showed, from his intimate acquaintance with the New Testament and the literature of the church, how in course of time Christianity had degenerated.
Favored and promoted by the anti-pope, Benedict XIII, of Avignon, Paul of Burgos rose higher and higher; he became bishop of Carthagena, chancellor of Castile and privy counselor to the king, Don Henry III. His malice did not succeed in prejudicing the king against the Jews, or inducing him to bar them from state employment. Don Henry had two Jewish physicians, in whom he reposed especial confidence. One, Don Meïr Alguades, an astronomer and philosopher, he appointed, perhaps in imitation of Portugal, to the chief rabbinate of the various Castilian communities. He was always in the king's train, and it is probable that to some extent he influenced him favorably towards his co-religionists. The other was Don Moses Zarzel (Çarçal), who celebrated in rich Spanish verse the long wished for birth of an heir to the Castilian throne, borrowing the beauties of the neo-Hebraic poetry to do honor to the newly-born prince, in whose hands, he prophesied, the various states of the Pyrenean Peninsula would be united. The calm, as between two storms, which the Spanish Jews enjoyed during the reign of Don Henry was favorable to the production of a few literary fruits, almost the last of any importance brought forth in Spain. None of these works was epoch-making; they were useful, however, in keeping alive the spirit of better times, and in preventing the treasures of Jewish literature from being forgotten. Profiat Duran managed to make people forget his baptism and to settle down quietly in Spain or Perpignan, where he commentated Maimuni's philosophy, and some of Ibn-Ezra's works. He also composed a mathematical and calendarial essay (Chesheb-Efod) and an historical account of the persecutions to which his race had been subjected since the dispersion. His best work is a Hebrew grammar ("Maasé Efod," written about 1403), in which he summarizes the results of older writers, rectifies their errors, and even attempts to formulate the principles of Hebrew syntax.
A production of more than common merit was written by Chasdaï Crescas, now on the brink of the grave, his spirits shattered by persecution. He was a profound, comprehensive thinker, whose mind never lost itself in details, but was forever striving to comprehend the totality of things. His scheme for a work treating, in the manner of Maimuni, of all phases and aspects of Judaism, investigating the ideas and laws out of which Jewish teaching had gradually developed, and reharmonizing the details with the whole where the connection had ceased to be apparent, bears witness to the extraordinary range of his learning and the perspicacity of his mind. The work was to be at once a guide to Talmudical study and a practical handbook. Death appears to have prevented the accomplishment of this gigantic enterprise, only the philosophic portion, or introduction, being completed. In this introduction Chasdaï Crescas deals, on the one hand, with the principles of universal religion, the existence of God, His omniscience and providence, human free-will, the design of the universe, and, on the other, with the fundamental truths of Judaism, the doctrines of the creation, immortality, and the Messiah.
Crescas was less dominated by the Aristotelian bias of mediæval philosophy than his predecessors. It had lost its halo for him; he perceived its weaknesses more clearly than others, and probed them more deeply. With bold hands he tore down the supports of the vast edifice of theory constructed by Maimuni on Aristotelian grounds to demonstrate the existence of God and His relation to the universe, and, conversant with the whole method of scholastic philosophy, he combated it with destructive force.
While the philosophy of his day appeared to him thus vague and illusory, he considered the foundations of Judaism unassailable, and set himself to show the futility of the criticisms of the former. The acknowledgment of Divine omniscience led him to the daring statement that man in his actions is not quite free, that everything is the necessary result of a preceding occurrence, and that every cause, back to the very first, is bound to determine the character of the final action. The human will does not follow blind choice, but is controlled by a chain of antecedent circumstances and causes. To what extent can the doctrine of reward and punishment be admitted, if the will is not free? Chasdaï Crescas' answer to this is that reward and punishment wait on intentions, not on actions. He who, in purity of heart, wishes to accomplish good—which must, of course, necessarily follow—deserves to be rewarded, as the man who willingly promotes evil, deserves punishment. The highest good to which man can aspire, and the end of all creation, is spiritual perfection, or bliss everlasting, not to be obtained, as the philosophers imagine, by filling the mind with metaphysical theories, but only through the active love of God. This is the substance of all religion and particularly of Judaism. From this point of view it may with justice be said that "the world was created for the sake of the Torah," for the aim of the Law is to lead to immortality by means of ideas and commandments and the guidance of thoughts and actions.
Chasdaï Crescas, the first to distinguish between universal religion and specific forms, such as Judaism and Christianity, propounded, deviating from Maimuni's system, only eight peculiarly Jewish tenets. His just objection to Maimuni's thirteen articles of faith was that they were either too many or too few, inasmuch as they blended indiscriminately fundamental truths common to all religions, and teachings peculiar to Judaism.
Together with Profiat Duran and Chasdaï Crescas, Don Meïr Alguades, the Castilian chief rabbi, appeared, in the brief interval between two bloody persecutions in Spain, as a writer of philosophic works. He was not an independent inquirer; he merely translated the ethics of Aristotle (1405, in collaboration with Benveniste Ibn-Labi) into Hebrew, making the work accessible to Jews, who, in practical life, lived up to its principles better than the Greeks, who produced them, or the Christians, who, in the pride of faith and church doctrine, considered themselves above the necessity of conforming to the requirements of morality.