 Next, he turns to Aristotle’s own account of nature and begins by chiding Aristotle for his cavalier assertion that trying to prove that natures exist is a fool’s errand, since it is self-evident that things have such (internal) causes. While we are immediately aware of motions and actions that seemingly proceed from substances of themselves, that there truly exist internal causes of these actions and motions is certainly in need of demonstration. Indeed, one who first encounters the motion of a magnet, Avicenna gives as an example, might imagine that its motion is a result solely of itself rather than of iron in the vicinity. Moreover, during Avicenna’s time the question of whether natures existed at all was a hotly debated topic between philosophers in the Graeco-Arabic tradition, like Avicenna, and thinkers in the Kalām tradition, the tradition of Islamic speculative theology and cosmology. 