John Buridan devotes an extensive discussion to final causality in two questions of his commentary on Book ii of the Physics: one asks whether the end is a cause (q. 7) and the other asks whether the necessity in natural operations derives from the end or from matter (q. 13). These two questions are the focus of this essay, which provides a detailed presentation of Buridan’s view, explaining its philosophical significance and setting it in the context of the medieval debate about final causality. It also points out the originality of Buridan’s view. Departing from the dominant medieval interpretation of Aristotle’s concept of the final cause, Buridan does not try to defend the idea that the end to which an action or change is directed is properly speaking a cause of that action, and in doing so he undermines the main assumptions at work in the Aristotelian account of finality in nature.

Powers explain how agents are able to act. Yet, Aquinas thinks that we must posit something further in a natural agent to account for why it exercises its power whenever it is possible to do so. Natural inclination is that impetus within natural agents that determines them toward action. This chapter examines Aquinas’s understanding of natural inclination and the role it plays in efficient causation. The chapter first considers Aquinas’s views on what natural inclinations are and why they are necessary. The chapter next considers his views on how natural inclinations explain how natural agents act for the sake of ends. Even though natural agents cannot know the ends for which they act, Aquinas thinks that they nevertheless act for the sake of goals through their natural inclinations. Lastly, the chapter examines Aquinas’s views on the ultimate cause of natural inclinations. Aquinas maintains that natural inclinations, and the natures upon which they follow, must have their ultimate causal source in a being with cognition, namely God. The chapter analyzes Aquinas’s rationale for this view.