Cognation between Cause and Effect from the Perspective of Avicenna and Mullasadra

The principle of cognation between cause and effect as one of the subsidiary rules of the principle of causality is an important issue in the history of Islamic philosophy, in such a way that the denial of this principle draws one to deny the principle of causality. The aim of this paper is to study this issue from the perspective of Avicenna and Mulla Sadra, as the two of the greatest Islamic philosophers. Regarding the Avicenna’s view, this study shows that he admits the principle of cognation as well as the rule of uniqueness (the rule of AlWahid) as two rational rules, but his other philosophical principles such as the principle of diversity of existent beings are not consistent with the principle of cognation between cause and effect. In Mulla Sadra’s perspective, based on his own philosophical principles such as principality of existence (asalat al-wujud), the gradational unity of existence, and the Possibility of indigence (imkan-I faqri) according to which, the existence of cause and effect are transformed into independent and relative existence, cognation of cause and effect finds new meaning.