DE MONARCHIA OF DANTE ALIGHIERI
CHAPTER VII: The Roman people were ordained for Empire by nature.
1. What nature has ordained comes to pass by Right, for nature in her providence is not inferior to man in his; if she were, the effect would exceed the cause in goodness,  which cannot be. Now we know that in instituting corporate assemblies, not only is the relation of members among themselves taken into account, but also their capacities for exercising office. This is a consideration of the limit of Right in a public body or order, seeing that Right does not extend beyond the possible. Nature, then, in her ordinances does not fail of this provision, but clearly ordains things with reference to their capacities, and this reference is the foundation of Right on which things are based by nature.  From this it follows that natural order in things cannot come to pass without Right, since the foundation of Right is inseparably bound to the foundation of order.  The preservation of this order is therefore necessarily Right.
2. The Roman people were by nature ordained for Empire, as may be proved in this wise.  Just as he would fail of perfection in his art who, intent upon the form alone, had no care for the means by which to attain to form; so would nature if, intent upon the single universal form of the Divine similitude,  she were to neglect the means thereto. But nature, being the work of the Divine Intelligence, lacks no element of perfection; therefore she has in view all media to the ultimate realization of her intent. 
3. As the human race, then, has an end, and this end is a means necessary to the universal end of nature, it follows that nature must have the means in view. Wherefore the Philosopher well demonstrates in the second book of Natural Learning that the action of nature is governed by its end.  And as nature cannot attain through one man an end necessitating a multiplicity of actions and a multitude of men in action, nature must produce many men ordained for diverse activities.  To this, beside the higher influence,  the virtues and properties of the lower sphere contribute much. Hence we find individual men and whole nations born apt for government, and others for subjection and service, according to the statement of the Philosopher in his writings concerning Politics; as he says, it is not only expedient that the latter should be governed, but it is just, although they be coerced thereto. 
4. If these things are true, there is no doubt but that nature set apart in the world a place and a people for universal sovereignty;  otherwise she would be deficient in herself, which is impossible.  What was this place, and who this people, moreover, is sufficiently obvious in what has been said above, and in what shall be added further on. They were Rome and her citizens or people. On this subject our Poet has touched very subtly in his sixth book, where he brings forward Anchises prophesying in these words to Aeneas, father of the Romans: "Verily, that others shall beat out the breathing bronze more finely, I grant you; they shall carve the living feature in the marble, plead causes with more eloquence, and trace the movements of the heavens with a rod, and name the rising stars: thine, O Roman, be the care to rule the peoples with authority; be thy arts these, to teach men the way of peace, to show mercy to the subject, and to overcome the proud."  And the disposition of place he touches upon lightly in the fourth book, when he introduces Jupiter speaking of Aeneas to Mercury in this fashion: "Not such a one did his most beautiful mother promise to us, nor for this twice rescue him from Grecian arms; rather was he to be the man to govern Italy teeming with empire and tumultuous with war."  Proof enough has been given that the Romans were by nature ordained for sovereignty. Therefore the Roman people, in subjecting to itself the world, attained the Empire by Right.
1. Conv. 2. 5. 4: "No effect is greater than its cause; because the cause cannot give what it does not possess. Whence, seeing that the Divine Intelligence is the cause of all things, and above all of human intelligence, the human cannot exceed the Divine."
2. Conv. 3. 15. 4: "The natural desire of everything is regulated according to the capacity of the thing desiring; otherwise it would oppose itself which is impossible, and nature would have made it in vain, which is also impossible." Cf. De Mon. 1. 3, notes 2 and 3.
3. Par. 1. 103: "All things whatsoever have an order among themselves; and that is form, which makes the universe in the likeness of God." Cf. De Mon. 1. 6, and notes.
4. See Conv. 4. 4. 4, and 4. 5, all the chapter.
5. See De Mon. 1. 8.
6. De Mon. 1. 3, notes 2 and 3; 2. 7, note 2. Also Par. 8. 97 ff., and Conv. 4. 24. 7: "Bountiful nature ... never fails to provide all necessary things."
7. Phys. 2. 2.
8. Par. 8. 122: "It behooves that divers must be the roots of the effects in you; wherefore one is born Xerxes, another Melchisedec, and another he who flying through the air lost his son.... A nature begotten would always make its course like its begetter, if the divine foresight were not stronger."
9. Conv. 4. 21. 2: "The soul ... as soon as produced, receives from the motive power of heaven its possible intellect, which creates potentially in itself all universal forms as they exist in its producer."
Purg. 30. 109: "By cooperation of the mighty wheels which direct every seed to some end according as the stars accompany."
10. Pol. 1. 5. 11.
11. Inf. 2. 20: "He [Aeneas] was in the empyrean heaven chosen for father of Rome our parent and of her empire, both which, if one say the truth, were established for the holy place where sits the successor of the sovereign Peter."
Conv. 4. 5. 2; 4. 5. 5: "A special origin and special growth, thought out and ordained by God, was that of the holy city. And certainly I am of the firm opinion that the stones which form her walls are worthy of reverence; and the ground on which she stands is worthy beyond all that has been preached and proved by men."
12. Note 6 above.
13. Aen. 6. 847 ff.
14. Aen. 4. 227 ff.