But, as it turns out, this argument is not original to Norris. Malebranche first uses this "argument from properties," as it is sometimes called in the secondary literature, in Elucidation 10, appended to the third edition of the Search (1678), and then again in the Dialogues on Metaphysics (1688). The only difference is that rather than using it as a negative argument to eliminate Cartesian nativism as a possible competitor to his own view, Malebranche uses it as an independent positive argument for the conclusion that ideas are in God. If anything, Norris' use of the argument is regressive for it figures in the argument from elimination that commentators have found problematic in Malebranche's philosophy and that Malebranche himself ultimately abandons in favor of positive arguments.
But Malebranche does not, in fact, abandon the negative argument, although it certainly becomes less important for his thought over time. The negative (or eliminative) argument is retained in the Search in every edition of the work revised by Malebranche, and is even developed by the addition of new arguments. Likewise, commentators have found Malebranche's eliminative argument problematic because it's difficult to see what the underlying principle of division is: he goes through several possibilities, and treats them as if they were comprehensive, but it is not obvious why they would be. Moreover, when Norris lays out the eliminative argument, he is quite clear that he is summarizing Malebranche on the subject. (His summary is quite admirable as a summary, in fact; it sets out all of Malebranche's main arguments without serious distortion but does so far more concisely than Malebranche does.)
Where Norris is really original, I think, is precisely where Nolan says he looks eclectic: that is, he takes scholastic arguments much, much more seriously than Malebranche did, and therefore takes the trouble to answer them. He recognizes, for instance, that one of the more powerful alternatives to the vision in God thesis is the scholastic doctrine of the agent intellect, and so (unlike Malebranche) takes the trouble to try to tear it down by argument. Even if this is merely on the critical side, it is innovative and new; no other early modern figure, even Leibniz, actually takes the trouble to argue against the schoolmen as systematically as Norris does, and thus actually face the challenge of the massive structures of argument and analysis they present. So we find throughout Norris extensive discussions of Malebranche and the scholastics.
Further, part of the reason a reader might think that Norris is unoriginal is that Norris is quite frank in his debt to Malebranche: if we trust Norris's own account (and we have no reason not to do so) Norris had worked his way to his basic position on his own and then found, as we would say, that he had been 'scooped' by Malebranche already, and that Malebranche had come up with several arguments he hadn't thought of. For Norris, one might say, philosophy is a cooperative venture in which people come together as students to learn from Truth itself, and consistent with this he goes out of his way to credit those who came up with ideas before he did, or who had developed arguments and ideas he did not; and when he thinks an argument needs to be rejected, he takes the trouble to try to understand the argument and show where it goes wrong. This is one of Norris's refreshing characteristics: many of the big names in the era also took arguments and ideas from others, but went through great lengths to cover the fact that they were doing so, and often avoid dealing with arguments by descending into ridicule.
And this raises the puzzle of why anyone would consider adjectives like 'eclectic' and 'derivative' to be so devastating a criticism of any historical philosopher as to make them unworthy of in-depth consideration. We already know that you can be eclectic and yet highly creative: Norris's eclecticism pales beside Leibniz's, but no one thinks 'eclectic' is some devastating indictment of Leibniz's creativity, because he is obviously creative. And so, too, is Norris, in his own way. Likewise, if we are going to penalize philosophers as being 'derivative' if they make use of the work of others without trying to hide the fact that they are doing so, we are in effect proposing a false and unsustainable view of philosophy, in which it is really the work of lonely and isolated geniuses who make up ideas and arguments whole cloth, and not at all of those who take these ideas and arguments and develop them in several ways. Norris certainly does develop things on his own, even if his starting points are derived from others. And, really, this is not really different from anyone else, even if other people are not so obvious and frank about what they owe to others. Unless the label 'derivative' is simply being used to say that someone added nothing new at all, it is a troublesome label to use: even creative geniuses aren't operating in a void, and even people who are not creative geniuses in a very narrow sense, but are largely just building on the work of others, can do philosophy. For Norris is right: philosophy is a cooperative venture.