Concerning the issue of “secondary philosophical intelligible”, Mulla Sadra tries, firstly, to prove externality of such concepts. Form what said by some great figures such as Mirdamad, he understands that though they think that such concepts are attributed in the external world, they do not consider an abstract or concrete mode in the external world as corresponding to these concepts. That is why Mulla Sadra elevates somehow external modes of such concepts to their external addition or occurrence; and in this, he accepts that there is some unity in terms of instances between them and thing they occur on them. In other words, Mulla Sadra thinks that, in spite of devotion of a share of external existence to each one of them, all such shares are gathered under a single instance and existence. Thus, this should be regarded as externality of different modes of a single thing. Hence, occurrence of such concepts is, in some sense (in the way of different modes of a single thing), external; but in some other sense (as completely abstracted things), they are mental. But, according to Principiality of Existence, the notion of existence, in its representativeness, represents the essence of the mode of reality rather than an accidental thing about it. But since, the notion itself does not constitute the real thing; it reveals only an aspect (not the essence) of it to the mind. Finally, he extends this analysis to other philosophical and even quiddative concepts.