In this chapter, we will discuss a small work of Aristotle entitled On the Heavens ¹; it contains a presentation of his astronomical and cosmological views. Many things have already been written about Aristotle's astronomy and cosmology² and to repeat them would go beyond the intended scope of this work, but a quick look at the method of Aristotle's cosmological speculations will be a useful supplement to our knowledge of his system of the philosophy of nature.