A Study of Ibn Sīnā’s Argument on the Accidental Nature of Unity in Ilāhīyyāt al-Shifā’

According to Aristotle, a number of philosophers in ancient Greece theorized that the “one” is an independent substance that performs a causal role in relation to other substances. Through clarifying the predicative nature of the “one” and referring to the false consequences of the above theory, he tried to reject it. Ibn Sīnā has extensively investigated the theory of the one’s being a substance and Aristotle’s related criticisms in the ilāhīyyāt section of al-Shifā’. Unlike Aristotle, he has not merely referred to the one’s being a predicate and, rather, through a lengthy and complex argument, has tried to demonstrate that unity, as the source of the derivation of the one, is a necessary accident. Ibn Sīnā’ argument is prone to criticism from different aspects, the most important of which is the confusion of categorical and analytic accidents with each other. Unity is merely an analytic accident, and Ibn Sīnā’s argument is incapable of demonstrating its being a categorical accident.