DE MONARCHIA OF DANTE ALIGHIERI
CHAPTER III: Of the three classes of our opponents and the too great authority many ascribe to tradition.
1. In entering on this third question,  let us bear in mind that the truth of the first  was made manifest in order to abolish ignorance rather than contention. But the investigation of the second  had reference alike to ignorance and contention. Indeed, we are ignorant of many things concerning which we do not contend: the geometrician does not know the square of the circle,  but he does not contend about it; the theologian does not know the number of the angels,  but he renders it no cause for quarrel; the Egyptian knows naught of the civilization of Scythia, but does not therefore make the civilization a source of strife. 
2. Now the truth of the third question has to do with so keen a contention that, whereas ignorance generally causes the discord, here the discord causes ignorance. For it always happens to men who will things before rationally considering them that, their desire being evil, they put behind them the light of reason; as blind men they are led about by their desire, and stubbornly deny their blindness.  Whence it often occurs not only that falsehood has her own patrimony, but that many men going out from her boundaries run through strange camps, where, neither understanding nor being understood at all, they provoke some to wrath, some to disdain, and not a few to laughter.
3. Three classes of men struggle hardest against the truth which we would establish.
4. First the Chief Pontiff, Vicar of our Lord Jesus Christ and successor to Peter, he to whom we should render not what is due to Christ but what is due to Peter, he, perchance in his zeal for the keys, together with some pastors of Christian flocks, and others moved solely, I believe, by their zeal for Mother Church, contradict the truth I am about to declare. They contradict it, perchance, from zeal, I repeat, not from pride. 
5. But others in their inveterate cupidity have quenched the light of reason, and call themselves sons of the Church, although they are of their father the devil.  Not only do they arouse controversy in regard to this question, but, despising the very name of the most sacred Princehood, impudently deny the first principles of this and the previous questions.
6. The third class, called Decretalists,  utterly ignorant and unregardful of Theology and Philosophy, depending entirely on the Decretals (which, I grant, are deserving of veneration), and I presume trusting in the ultimate supremacy of these, derogate from the imperial power. Nor is it to be wondered at, for I have heard one of them aver and insolently maintain that ecclesiastical traditions are the foundation of faith. Let those dispel this error of thought from mortal minds whom the world doubts not to have believed in Christ, the Son of God, ere ecclesiastical traditions were, believed in Him either to come, or present, or having already suffered,  and believing hoped, and hoping burned with love, and burning with love were made co-heirs with Him. 
7. And that such mistaken thinkers may be wholly shut out from the present discussion, it must be observed that some of the Scriptures take precedence of the Church, some are equivalent to the Church, and some subordinate to it.
8. Those taking precedence of the Church are the Old and New Testaments, which, as the Prophet says, "were commanded for ever,"  and to which the Church refers in saying to the Bridegroom, "Draw me after thee." 
9. Equivalent to the Church are those Councils so worthy of reverence, and in the midst of which no believer doubts the presence of Christ; for we have, according to Matthew's testimony, the words spoken to His disciples at His ascension into heaven: "Lo, I am with you always, even unto the end of the world."  In addition, there are the writings of the Doctors, Augustine,  and others, and whosoever doubts the aid of the Holy Spirit therein has never seen their fruits, or if he has seen, has never tasted them.
10. Subordinate to the Church are the traditions called Decretals, which, while they must be revered for their apostolic authority, must nevertheless be held unquestionably inferior to the fundamental Scriptures, seeing that Christ rebuked the priests for not so doing. When they had inquired, "Why do thy disciples transgress the tradition of the elders?"  (for they had omitted the washing of hands) Christ answered, as Matthew testifies, "Why do ye also transgress the commandment of God by your tradition?" Here the inferiority of tradition is clearly implied.
11. If, as we believe, traditions of the Church are subordinate to the Church, authority necessarily accrues not to the Church through traditions, but to traditions through the Church. And I repeat, those who have faith in traditions alone are excluded from this discussion. For they who would hunt down this truth must start in their search from those writings whence the authority of the Church emanates.
12. Others must likewise be excluded who, decked in the plumage of ravens, boast themselves white sheep of the Master's flock. In order to carry out their crimes, these sons of impiety defile their mother, banish their brethren, and scorn judgments brought against them. Why should reason be sought in behalf of these whose passions prevent them from understanding our basic principle? 
13. There remains, then, the controversy with those only who, led by a certain zeal for their Mother the Church, are blind to the truth we are seeking. And with them, confident in that reverence which a loyal and loving son owes to father and mother, to Christ and the Church, to the Shepherd and all who profess the Christian religion, I enter in this book into combat for the preservation of truth.
1. "Whether the authority of the Roman Monarchy derives from God immediately, or from some vicar of God."
2. "Whether temporal Monarchy is necessary for the well-being of the world."
3. "Whether the Roman people rightfully appropriated the office of Monarchy."
4. Conv. 2. 14. 12: "The circle by reason of its arc cannot be exactly squared."
Par. 33. 133: "As is the geometer who applies himself wholly in order to measure the circle, and finds not by thinking that principle whereof he is in want, such was I."
In 1761 Lambert proved that the ratio of the circumference of a circle to its diameter was incommensurable. Lindemann has since demonstrated that this ratio was transcendental, and that the quadrature of the circle by means of the rule and compass only is impossible.
5. The number of the angels Dante discusses in Conv. 2. 6, concluding in chapter 2. 6. 2: "It is proved to us that these creatures exist in immense numbers; because His Spouse and Secretary, the Holy Church ... says, believes, and preaches that these most noble creatures are almost innumerable; and she divides them into three hierarchies."
6. Eth. 3. 3. 6: "About things eternal no man deliberates, as about the world, or the diagonal and the side of a square, that they are incommensurable, ... nor about things accidental, as the finding of a treasure, nor yet about everything human, as no Lacedaemonian deliberates how the Scythians might be best governed." Moore thinks that Dante's substitution of "Egyptian" for "Lacedaemonian" was merely a slip of memory.
7. Purg. 18. 16: "Direct toward me the keen eyes of thy understanding, and the error will be manifest to thee of the blind who make themselves leaders." So wickedness to Dante was largely a matter of ignorance, of blindness, of inability to understand. With sight and comprehension of good came right action.
8. Dante even in his moments of greatest indignation had only reverence for the papal office. Inf. 19. 100: "Were it not that still forbids it to me my reverence for the supreme keys which thou heldest in the glad life, I would use words yet more grievous;" so he says to Pope Nicolas placed among the simoniacs in Malebolge. And of the persecution of Boniface VIII, whom Dante hated above all men, he writes Purg. 20. 86: "I see the fleur- de-lys enter into Alagna, and in his Vicar Christ himself made captive. I see Him being mocked a second time, I see the vinegar and the gall renewed, and Him between live thieves put to death. I see the new Pilate so cruel that that sates him not, but without decree he bears into the temple his greedy sails."
9. John 8. 44: "Ye are of your father the devil, and the lusts of your father ye will do." For cupidity as the greatest of human sins, see De Mon. 2. 12. 1; 1. 1. 5, and note 12. The worst form of cupidity was simony, trafficking in spiritual matters, shown forth in Inf. 19. 1 ff.: "O Simon Magus! O unhappy followers! because the things of God, which ought to be spouses, and ye in your greed make to commit whoredom for gold and for silver -- now it is meet that for you the trumpet sound, seeing that in the third pit ye are stationed."
Letter 9. 7 To the Italian Cardinals: "Every one has taken Cupidity to wife, even as ye have, -- Cupidity, who is never, like Charity, the mother of Piety and Equity, but always of Impiety and Iniquity. Ah, most holy Mother, Bride of Christ, what sons dost thou bear of water and of the spirit to shame thee! Neither Charity nor Justice, but the daughters of the horse-leech have become thy daughters-in-law, and all save the Bishop of Luni attest what kind of sons they have brought to thee. Thy Gregory lies among the cobwebs; Ambrose lies on the neglected shelves of the clergy; Augustine lies forgotten; Dionysius, Damascenus, and Bede have been thrown aside; and I know not what Speculum, Innocent, and he of Ostia preach. Wherefore is this? They sought God as their end and best good; these run after riches and benefices."
10. Two of these men are named Par. 12. 83, Henry of Susa, Archbishop of Embrun and Cardinal of Ostia, and Thaddeus of Bologna. In Letter 9. 7, quoted in the note preceding, the Speculum of Guglielmo Durante, Innocent III, and the Cardinal of Ostia make another list.
The Decretals were those papal decrees which form the groundwork of the ecclesiastical law. The most important compilation was issued by Gregory IX in 1234. The Code of the Papal Decretals was promulgated as the statute law of Christendom, the authority of which was superior to all secular law. See Toynbee, Dict. s. v. Decretali; Hallam, Middle Ages, Ch. 8, part 2.
Par. 9. 133: "For this the Gospel and the great Doctors are deserted, and study is given to the Decretals alone, as appears on their margins."
11. Par. 20. 103: "They issued not from their bodies as thou deemest Gentiles, but Christians, in firm faith, he of the Feet that should suffer, he of them having suffered."
12. Rom. 8. 16, 17.
13. Ps. 111. 9. This is a rather strained interpretation of "He hath sent redemption unto his people; he hath commanded his covenant for ever."
14. Cant. 1. 4. Dante, as was customary in his times, interprets the Canticles allegorically as applying to the Church.
15. Matt. 28. 30.
16. St. Augustine (354-430). Dante quotes in the next chapter from two of his works, De Civitate Dei and De Doctrina Christiana. The ideals of Augustine in the former treatise and those of Dante in the De Mon. are very similar. For his relation to Dante see Moore, Studies, Vol. 1. pp. 291-294. Augustine is honored with a seat in the Celestial Rose by St. Francis and St. Benedict Par. 32. 35. For further mention of him see note 9, above.
17. Matt. 15. 2, 3.
18. Phys. 1. 2. "Cupiditas" is the word I have this time translated "passions." Cf. Purg. 19. 121: "As avarice extinguished our love toward every good, whence labor was lost, so justice here holds us straitly bound." See also note 9, above.