The Proof of the Truthful (Burhān al-Ṣiddīqīn) remains a focal point of philosophical disputes between Avicennian and Sadraean readings. While defenders of the Avicennian proof validate it by adapting Avicenna’s principles to the primacy of existence (aṣālat al-wujūd) and ontological poverty (imkān-i faqrī), critics cite textual evidence of his non-adherence to these principles. Moving beyond these controversies via a descriptive-analytical method, this research demonstrates that the Avicennian proof’s robustness does not depend on his commitment to later Sadraean principles.

Findings indicate that Avicenna’s highest level of proof relies on the “principle of reality”—a reality even a sophist must accept. This is achieved through the “self-evidence of the concept of the existent and necessity” (in the Metaphysics of al-Shifāʾ) and restricting “eternal necessity” (ḍarūrat-i azalī) exclusively to God in logic and philosophy. Proving the Necessary Being (Wājib al-Wujūd) is therefore not a theoretical deduction from ontological poverty, but a “reminder” of necessity’s essential referent.

Thus, Avicenna’s proof entails multiple degrees. At its highest level, avoiding the dichotomy of quidditative contingency (imkān-i māhuwī) and ontological poverty, it proves God through reality itself. It utilizes the established intrinsic convergence among “reality,” “eternal necessity,” and the “Necessary Being,” subsequently articulating more theoretical dimensions in its lower degrees.