Al-Fārābī on Future Contingency

Aristotle discusses logical determinism (LD) in De Interpretatione 9. In his commentary on Aristotle’s work, al-Fārābī explains his own view about logical and theological determinism (TD). Analysing al-Fārābī’s understanding of the notion of (in)definiteness and the role it plays in (the interpretations of) Aristotle’s solution to LD, I argue that al-Fārābī’s solutions to TD and LD are radically inconsistent with the solution to LD that he attributes to Aristotle. Although it might initially seem otherwise, the source of this inconsistency is not that al-Fārābī’s understanding of the notion of (in)definiteness in his discussion of Aristotle’s solution to LD is different from his understanding of this notion in the development of his own solutions to LD and TD. I show that al-Fārābī has not changed his mind in this regard. Rather, the tension between the two approaches stems from the fact that, by contrast with Aristotle (or, more precisely, with al-Fārābī’s Aristotle), al-Fārābī does not think that the truth-values of Future Contingent Propositions (FCPs) are indefinite. However, he also does not believe that the definiteness of the truth-value of a proposition rules out the contingency of its content.