Instances of Al-Wahid Rule in Mulla Sadra's Philosophy

One of the important rules that Mulla Sadra has stated in his philosophy, as his preceding philosophers did, is the "Al-Wahed Rule (the one does issue him only the one)". He proclaims that this rule is justifiable purely by reason, and discusses the content of this rule in a way comparable to that of his predecessors. However, given his views on the personal unity of existence, the “Basit al-Haghigha” rule, the substitution of causation and monotheism (Tawhid) with manifestation and evolution falls short of exemplifying this philosophy. Raising Basit al-Haghigha rule and rejecting causality in its common sense underline the personal unity of existence. Therefore, no being other than God will have a true existence, and all beings are nothing but shadows and manifestations of that true being. By rejecting duality in existence, the Al-Wahed rule loses its conventional instances, as Sodur (emanation) in this rule is secondary to duality and plurality.