I want here to briefly look at what I think is a serious problem that is entailed as a result of Nasir Khusraw’s (d.1060) way of argumentation for a distinctly Ismaili thesis i.e., of the Divine Command. Before I do that, let me first quote the relevant passage which gives rise to this problem. In the section on ontology of part II of his Gushayish wa rahayish, Nasir Khusraw writes:
Know, O brother, that the existent is of two kinds: one is called necessary and the other contingent. The necessary is higher than the contingent existent because without the necessary existent the contingent cannot exist. […]. According to this explanation, the entire world is a contingent existent which cannot come into existence without the necessary existent. Inevitably, the maker of the world has to be a necessary existent, because if we say that it is a contingent existent, then it should also have a necessary existent. Then let us stop at this point and say that the creator of the world is a necessary existent whereas the world itself is a contingent existent, just as a date-stone is like a contingent existent because from it the palm-tree may or may not come into existence. Since, as we mentioned, the existent is of two kinds and both of them are species, and whatsoever is a species must have a genus, it is inevitable for the genus to be superior to both the species, the necessary and contingent, in rank and not in time or anything else. That is the Command of God – may His name be mighty – which is the Absolute Existent, the existent which has come into existence not from an existent. Under [the Command] are the necessary existent, which is the (Universal) Intellect, and the contingent existent, that is, the (Universal) Soul, which is under the [Universal] Intellect.
Basically, the problem is this. Assume three points: (1) Nasir Khusraw’s description of the necessary existent, call it (N), as higher than the contingent (C) because the latter would not exist without the former; (2) that these two kinds of existents are species of a genus (which is a very problematic move on his part, but that aside for now); and as a conclusion (3) that there then must be something above them (because species must have a genus), which he terms the Command (CC) and which brings them into existence. Now given these three propositions, why then does he not just consider the Command to be the true or real necessary existent since the other two i.e., (N) and (C), would not exist without it? It seems to me, given (2) above, he would have to do that because how he described what is necessary and contingent. That is, (N) and (C) would not exist without (CC). But if he does treat (CC) as now the real necessary existent, then the previous (N) will become, along with the first (C), contingent as well. Call the (N) that became a contingent (C1). It’s fairly straight-forward why this is so i.e., because (C1), which was previously the necessary existent, would not exist without (CC)). As a result, we’ll now have (CC), which is the real necessary existent, and (C) and (C1), both of which are contingent existents. But then Nasir Khusraw will have to treat these three existents as species of a genus (since that is what he did with the first two in order to derive the existence of (CC)). And if that’s so, there will then have to be something superior or above (CC). This new superior thing, call it (CCC), that’s above (CC) will now be the real necessary existent. However, if that is so – and this is the serious problem which I mentioned at the beginning – the process will then have to regress infinitely, with ever more C’s being generated. But that, I think Nasir would agree, is absurd.