The concept of efficient causation originates with Aristotle, who states that the types of cause include ‘the primary source of the change or rest’. For Medieval Aristotelians, the scope of efficient causality includes creative acts. The Islamic philosopher Avicenna is an important contributor to this conceptual change. In his Metaphysics, Avicenna defines the efficient cause or agent as that which gives being to something distinct from itself. As previous studies of Avicenna's ‘metaphysical’ conception of the efficient cause attest, it takes (...) God as a model agent. This essay considers whether Avicenna's ‘metaphysical’ conception of the efficient cause applies to natural agents. It ultimately argues that Avicenna offers a unified view of the efficient cause, which includes both divine and natural agents. On this view, an efficient cause gives being to another and is simultaneous with its effect. While Avicenna's defence of this view is an important chapter in the history of the concept of the efficient cause, it is also of interest in its own right. By appeal to a version of the principle of sufficient reason, it challenges a widespread view that causes are temporally prior to their effects. (shrink)

This paper presents Duns Scotus’s theory of mixture in the context of medieval discussions over Aristotle’s theory of mixed bodies. It revisits the accounts of mixture given by Avicenna, Averroes, and Thomas Aquinas, before presenting Scotus’s account as a reaction to Averroes. It argues that Duns Scotus rejected the Aristotelian theory of mixture altogether and that his account went contrary to the entire Latin tradition. Scotus denies that mixts arise out of the four classical elements and he maintains that both (...) the elemental forms and the elemental qualities are lost in the mixture. Consequently, he denies the distinction between the process of mixture and that of substantial change through generation and corruption. The reassessment of Scotus’s account modifies the current historical representation of this discussion, inherited from Anneliese Maier. (shrink)

I use Plotinus to present absolute divine simplicity as the consequence of principles about metaphysical and explanatory priority to which most theists are already committed. I employ Phil Corkum’s account of ontological independence as independent status to present a new interpretation of Plotinus on the dependence of everything on the One. On this reading, if something else (whether an internal part or something external) makes you what you are, then you are ontologically dependent on it. I show that this account (...) supports Plotinus’s claim that any entity with parts cannot be fully independent. In particular, I lay out Plotinus’s case for thinking that even a divine self-understanding intellect cannot be fully independent. I then argue that a weaker version of simplicity is not enough for the theist since priority monism meets the conditions of a moderate version of ontological independence just as well as a transcendent but complex ultimate being. (shrink)

The study begins with the language employed in and the psychological basis of thought experiments as understood by certain medieval Arabic philosophers. It then provides a taxonomy of different kinds of thoughts experiments used in the medieval Islamic world. These include purely fictional thought experiments, idealizations and finally thought experiments using ingenious machines. The study concludes by suggesting that thought experiments provided a halfway house during this period between a staunch rationalism and an emerging empiricism.