The principle known as the possibility of the nobler (qāʿidat imkān al-ashraf) is arguably one of the most often employed principles in later Islamic philosophy. In its standard formulation it states that if something baser exists, a nobler thing must have existed prior to it. A similar argument from the degrees of perfections has had a long career in the history of Western philosophy as well, with its beginnings reaching Stoicism. In Christian theology and philosophy it serves most importantly as a proof for the existence of God in the so-called henological argument of Aquinas. In Islamic philosophy it directly derives from the ex uno non fit nisi unum principle. Since the formulation of its standard version by al-Suhrawardī, the validity of the principle has been conditioned on that it is only applicable to the intelligible beings, hence its main objective is to offer a proof for the existence of the intellects. The article analyzes the application of the principle in Ṣadrā’s philosophy and enquires about its historical roots.