Introduction to Astronomy

in our greater tables at the end of the richene elchebir Al-Zij al-Kabir, or Great Astronomical Table, I have followed the celestial courses; and we too follow them. The second natural science, truly, in its own kind, is no less universal; it first leads to the natures and properties of stellar bodies, and then to the leadership governance/influence of accidents of the inferior world, partly through certain frequent experiments, and partly through a certain natural speculation. From this, indeed, because various courses of the stars follow the different variations of the elements in elemental things by a customary and certain law, it seems a necessary argument that this does not happen without some natal movement of those stars in these the elements. There is, therefore, a part of this science which, standing by itself, follows the less manifest reason of nature through a certain guidance, so that those who judge this science are not found to be ignorant of either many experiences of these things, or of the things themselves.

A woodcut depicts the personification of the Sun (Sol). A crowned figure is seated in a chariot drawn by four galloping horses. He holds reins in his right hand and a tall staff surmounted by a cross in his left. Radiant sunbeams emanate from both the figure's head and the chariot's wheel. The wheel contains a lion symbol, representing the zodiac sign Leo, in which the Sun is domiciled.

Therefore, the lights the Sun and Moon carry certain signs where they are principally the most notable of all celestial bodies. And in the first place, the Sun: for no one is ignorant that the legitimate successions of the times of the year affect the elements with customary alterations in an orderly manner.