 One might, though, be tempted to argue that this concentration on causality is simply an effect of reading Aristotle, but this would be too hasty. Medieval thinkers were attracted to the problem of causality long before most of Aristotle’s texts became available in the thirteenth century: already in the twelfth century the created universe was seen as a rational manifestation of God (Wetherbee 1988, p. 25), and, consequently, the rational investigation of the universe was seen as a way of approaching God: “In the creation of things”, says William of Conches, “divine power, wisdom and goodness are beheld” (William of Conches, Glosa super Platonem, p. 60). This consideration of the relation between the natural world and God continues throughout the Middle Ages: for example, Duns Scotus’ proof of the existence of God is an a posteriori modal proof, based on the notion of causality (Craig 1980; Normore 2003; Ross and Bates 2003).