Possibility and Probability in Avicenna's View

Abstract

In his book "al-Shifā" (The Healing), Avicenna distinguishes between the concepts of possibility and probability and presents three approaches to differentiate these two concepts, although it is evident from the conducted studies that he did not specifically and independently address the issue of probability. In this study, we investigate the distinction between possibility and probability based on the Avicenna's works. The findings suggest that the distinctions which Avicenna made between possibility and probability are rooted in their specific historical contexts. Although most logicians maintain that probability is subjective and possibility is objective, they cannot draw a precise distinction between the two concepts. The second distinction is, in fact, between the future-possibility and the probability of occurrence of an event in the future, which reflects the difference between Avicenna's future-possibility and Al-Fārābī's future-possibility. The third distinction also seems to be a confusion between the meanings of the words 'probability' and 'narrowest-possibility', which has its roots in the translation of Aristotle's works.