DE MONARCHIA OF DANTE ALIGHIERI
CHAPTER IV: To attain this end humanity requires universal peace.
1. It has now been satisfactorily explained that the proper function of the human race, taken in the aggregate, is to actualize continually the entire capacity of the possible intellect, primarily in speculation, then, through its extension and for its sake, secondarily in action. And since it is true that whatever modifies a part modifies the whole, and that the individual man seated  in quiet grows perfect in knowledge and wisdom,  it is plain that amid the calm and tranquillity of peace the human race accomplishes most freely and easily its given work. How nearly divine this function is revealed in the words, "Thou hast made him a little lower than the angels."  When it is manifest that universal peace is the best of those things which are ordained for our beatitude. And hence to the shepherds sounded from on high the message not of riches, nor pleasures, nor honors, nor length of life, nor health, nor beauty; but the message of peace. For the heavenly host said, "Glory to God in the highest, and on earth peace among men in whom he is well pleased."  Likewise, "Peace be unto you"  was the salutation of the Saviour of men. It befitted the supreme Saviour to utter the supreme salutation. It is evident to all that the disciples desired to preserve this custom; and Paul likewise in his words of greeting. 
2. From these things which have been expounded we perceive through what better, nay, through what best means the human race may fulfill its proper office. Consequently we perceive the nearest way through which may be reached that universal peace toward which all our efforts are directed as their ultimate end, and which is to be assumed as the basic principle of subsequent reasoning. This principle was necessary, we have said, as a predetermined formula, into which, as into a most manifest truth, must be resolved all things needing to be proved. 
1. Sedendo et quiescendo." Dante often used the figure of the seated person to portray the life of contemplation.
S. T. 2-2. 182. 2: " Contemplative life consists in a certain stillness and rest according to the text, 'Be still, and know that I am God,'" Ps. 46. 10. Also S. T. 1- . 3. 4, 5.
Conv. 4. 17. 16: "And Mary ... sitting at the feet of Christ, took no heed to the service of the house ….. For if we explain this morally, our Lord wished thereby to show us that the contemplative life is the best, although the active life is good.” L.c. 1. 1. 4: “Blessed are the few that are seated at the table where the bread of the angels is eaten.”
Purg. 27. 105: “My sister Rachel never is drawn from her mirror, and sits all day."
2. Eccles. 38. 25 (Vulg.): “The wisdom of a learned man cometh by opportunity of leisure; and he that hath little business shall become wise."
3. Ps. 8. 6; cf: Heb. 2. 7. Quoted Conv. 4. 19. 3.
4. Luke 2. 14.
5. Luke 24. 36; John 20. 21, 26.
6. Rom. 1. 7.
7. Some of Dante's most eloquent exhortations in prose and some of the most perfect music of his verse are touching that peace which he knew should make man happy on earth and blessed in heaven, that peace which he went to seek "from world to world," and which he found at last in complete obedience to the will of God.
Purg. 3. 74: Virgil conjures the spirits "By that peace which I think is awaited by you all."
Purg. 5. 61: Dante here tells of "that peace, which makes me, following the feet of a guide thus fashioned, seek it from world to world."
Purg. 10. 34: "The angel that came on earth with the decree of the many years wept-for peace .... opened Heaven from its long interdict."
Purg. 11. 7: "Let the peace of thy kingdom come to us."
Purg. 21. 23: "My brethren, God give you peace," is the greeting of Statius.
Purg. 28. 91: "The highest Good, which does only its own pleasure, made the man good and for good, and gave him this place for an earnest to him of eternal peace."
Purg. 30. 7: "That truthful folk ... turned them to the car as to their peace."
Par. 2. 112: "Within the heaven of the divine peace revolves a body in whose virtue lies the being of all that is contained in it."
Par. 3. 85: "In His will is our peace."
Par. 27. 8: "A life complete of joy and peace."
Par. 30. 100: "Light is there on high, which makes visible the Creator to that creation which only in seeing Him has its peace."
Par. 31. 110 : St. Bernard "in this world by contemplation tasted of that peace."
Par. 33. 1: "Virgin Mother ... in thy womb was rekindled the Love, through whose warmth in the eternal peace this flower has thus sprung."