General Uranometric Directory (Directorium Generale Uranometricum)

regarding the correction of the calendar and the determination of the proper celebration of Easter and the movable feasts Religious festivals like Easter that do not fall on a fixed date each year. Their dates are calculated based on the cycles of the sun and moon.. They were so concerned with these matters that they seem to have highly recommended astronomy to churchmen as a very useful tool for the Christian Commonwealth. Therefore, we should be led by the example of so many excellent men. We should turn our eyes away from this busy investigation of earthly things, which nature has even granted to beasts. Instead, we should turn our sight toward the heavenly lights. It seems that the Wisdom of God has reserved such sublime things for humans, having denied these senses to other creatures. As the most elegant poet sang in the first book of the Metamorphoses:

original: "Pronaq; cum spectent animalia caetera Terram / Os homini sublime dedit, Coelumq; tueri." From Ovid, Metamorphoses, Book 1.

What sweetness will we not taste in learning these things? How much knowledge of divine matters will we enjoy? How many sublime concepts of the magnificence and omnipotence of God will we form? For as Psalm 18 In modern bibles, this is typically Psalm 19. truly testifies: The heavens declare the glory of God, and the firmament proclaims the work of his hands. But who will be the most faithful companion for investigating things so high, so noble, and so remote from us? It is The Doctrine of Trigonometry. By placing triangles one upon another, this doctrine links them together with appropriate bonds. Unlike the Giants who piled mountain upon mountain—Pelion upon Ossa and Olympus upon Pelion—to wage war against Heaven, we do not need to fear the lightning of an angry Jove. Instead, I believe we will find the First Mover An Aristotelian concept referring to the primary cause of all motion in the universe, often identified with God. favorable and kind to our prayers as we study His secrets.

In this way, we shall look upon the brilliant face of the Sun without blinking. We shall follow the very swift course of the Sky without great physical exhaustion. We shall preserve through memory times that were almost forgotten. After many centuries, we shall still grasp future events without being worn down by old age. We shall learn the celestial dances without confusion. The common people think they see a confused crowd of night-lights. However, as we look deeper into the heart of the Sky, we shall see a most orderly Theater of vast and glowing bodies. This theater was built by the Supreme Artisan of all things. In it, we may gaze upon His inaccessible and invisible light through so many kindled torches, as far as is permitted to us. Others who later sense our happiness will be compelled to cry out with one voice:

original: "Felices animae quibus haec cognoscere primum, / Inq; domos superas scandere cura fuit." From Ovid, Fasti, Book 1.