Muslim philosophers have regarded sensations, also known as propositions concerning the external world, as secondary self-evident propositions. According to Avicenna, although these secondary self-evident propositions are open to debate, they do not require further argumentation and are therefore considered self-evident. However, Mulla Sadra posits that real self-evident propositions are exclusive to "primary self-evident propositions," while secondary self-evident propositions are inherently "theoretical." Consequently, Avicenna deems the external world to be self-evident, whereas Sadra perceives it as theoretical and in need of proof. Our aim is to demonstrate that not only is Avicenna's perspective contradictory, but it also necessitates relativity and gradation of self-evident propositions, both of which are untenable. We concur with Sadra's viewpoint that secondary self-evident propositions are not truly self-evident but rather theoretical. Moreover, we reject the notion of relativity and gradation in self-evident propositions, affirming that genuine self-evident propositions are exclusive to "primary self-evident propositions" and that the existence of the external world is theoretical, requiring proof. This article employs an analytical-comparative-critical approach.