One of Mūllā Ṣadrā’s logical innovations based on the theory of the primacy of existence is that “the definition of an object is unique to its recent differentia”. Mūllā Ṣadrā believes that in order to achieve true unity in composite quiddity, it is necessary to gather all the previous genuses and differentias in existence or in the same recent Form and differentia; in other words, in the recent Form and differentia, they are merged and depreciated. One of the consequences of such an attitude towards the recent Form and differentia - as the provider of the true unity of the composite quiddity - is that the previous materials and genuses are integrated in a simple way in the recent chapter, but each one, in a detailed way (that is, with actualities multiple) are not the constituents of the compound object and are considered outside of its truth. The inevitable result of the above point is that the inclusion of previous genuses and differentias in the definition of quiddity is not as an intrinsic component of that, but as equipment or branches of quiddity. Ṭabāṭabāʼī, as one of the most important commentators on Mūllā Ṣadrā’s view, did not accept this view and proposed three objections to it: 1) it is not appropriate to be content with the differentia alone; while the “definition” must be detailed 2) the exclusion of previous genuses and differentias from the truth of the object requires a revolution in essence 3) The exclusion of the genuses and differentias from the truth of the object is in conflict with “dress after dress” in the substantial motion. This article, after a brief reference to Mūllā Ṣadrā’s view on the uniqueness of the definition of an object through its recent differentia, presents Ṭabāṭabāʼī’s threefold criticisms with a critical attitude. Examination of these three criticisms led to the conclusion that none of Ṭabāṭabāʼī’s criticisms is correct and that Mūllā Ṣadrā’s intention is to exclude the genuses and differentias present in the detailed order, not the genuses and differentias mentioned in the brief and simple order of the recent differentia. Also, during the study and response to Ṭabāṭabāʼī’s criticisms, some of the hidden dimensions of Mūllā Ṣadrā’s view, such as the affirmative actuality of the genuses and the previous differentias.