Commentary

In this chapter Levi indicates that his goal is to present an astronomical theory that is satisfactory both from a mathematical and a philosophical point of view. He remarks that this had not been achieved in the past, but he does not criticize any of his predecessors by name. In fact, there are very few authors cited anywhere in his astronomical writings, and none of them was his contemporary. We are told that to complete this task in astronomy, the investigator must be skilled in both mathematics and natural philosophy because this task cannot be split up (§§ 14–17). Levi’s views are similar to those of Ibn al-Haytham (see Introduction), and I am inclined to believe that Levi knew of them: for another example of similarities between the views of Levi and Ibn al-Haytham, see the commentary to chapter 2.