I am optimistic about the potential of the powers-based approach, but I see its major barrier to success to be bridging the gap between itself and other systems, or at least, clearly situating itself with respect to the dominant dialectic. Many advocates of more traditional approaches see the powers-based system as operating within its own philosophical universe and making little contact with the existing framework. This hurts both sides: powers-based theories are only taken seriously by those antecedently friendly to them, and prevailing approaches do not benefit from the theoretical resources of the powers approach. At the same time, using the tools of the more dominant strategies would benefit powers-based theories, as some of their key concepts (properties and substances, to name a few) remain underdeveloped. Clearly connecting powers-based theories to the traditional Humean framework will open up greater theoretical resources for both sides.--Sara Bernstein reviewing at NDPR. [Letters added to facilitate discussion.]
This quoted passage is the closing paragraph of Bernstein's very informative and stimulating review. (What follows is in no sense criticism of Bernstein.) I read Bernstein as identifying the "traditional Humean framework" (i.e., Lewisian metaphysics) as the more "dominant" approach to metaphysics at present. I read her as describing the "powers-based" (i.e., a neo-Lockean or, more accurately, neo-Aristotelian) approach as the weaker party. Let's stipulate that Bernstein's judgment on the relative strength of both parties in analytical metaphysics is accurate (see also Troy Cross's recent reviews, here and here). Even so, her review raises some uncomfortable questions about the state of the discipline. Here I focus on three features: (i) the existence of sub-disciplinary echo-chambers; (ii) who gets to decide who should respond to who; (iii) the benefits, if any, of philosophical engagement.
Some such echo-chambers can be useful. They function the way ancient 'schools' did. With like-minded folk one can develop distinctions and argumentative moves while agreeing on important background assumptions before one has to address potential knock-down arguments. They also facilitate non-trivial sociological benefits--they allow for the development of citation networks and for categorization of one's position/approach. A lot of folk, enchanted by Kuhnian images of science, also believe that such echo-chambers are necessary for increased problem-solving capacity (recall my criticisms of PANS ["philosophy as normal science"]). Of course, they wont call it "echo-chambers!"
Second, Bernstein clearly wishes to see more engagement between the powers-based and Humean approaches with intellectual benefits promised for both sides, and one can read her book-review as an attempt at facilitating such engagement. Interestingly enough, in her report on the perceptions of the dominant party, the burden of effort is on the weaker philosophical party--the philosophical powers-based upstarts.* As a fact about social power this is undoubtedly accurate; the haves can afford to ignore the not-haves. Let's call this the "it's-okay-to-ignore-them-mechanism." This mechanism is extremely common in professional philosophy; it is mostly very innocent (life is short, demands on time great, much is junk etc.), but sometimes it leads to insidious consequences (e.g., male-only citation networks, philosophical hubris, unacknowledged philosophical problems, etc.) It is rare to see reports of the it's-okay-to-ignore-them-mechanism in print.
As a matter of courtesy or social justice it is, of course, not obvious why the burden of effort ought to be on the socially weaker party to make philosophical "contact" with "the existing framework." Even if the "dominant" party is nice and open-minded about it, it remains an obnoxious stance.
As a philosophical stance, the it's-okay-to-ignore-them-mechanism is also not very philosophical. Rather than go hunting for philosophical treasures and nuggets of truth elsewhere, it bespeaks of a status-quo bias. Such bias would be fine, of course, if the world was being showered with philosophical truths (and, of course, there are plenty of folk that love to be cheer-leaders of our progress). Even if one were to grant areas of impressive progress in contemporary philosophy, a lot of philosophical problems are, well, either intractable (that's why they are philosophical, after all) or their purported solutions rely on questionable, primitive commitments or arbitrary score-keeping rules.
But the it's-okay-to-ignore-them-mechanism is, in fact, not the most objectionable mechanism on offer by the "dominant" folk as reported by Bernstein; far more pernicious is the demand that the inferior party articulate its own position with respect to the "dominant dialectic." For, doing so, guarantees that it will remain the weaker dialectic; the dominant dialectic is after all, fine-tuned on an impressive set of achievements (otherwise it wouldn't be "dominant" or clear, or whatever). Luckily, while the "dominant dialectic" may be the most important tribunal of philosophy, the ultimate authority is truth (and she has her ways of overturning the judgments of that tribunal).
Third, it's great that there are distinctive philosophical traditions in contemporary of philosophy; that despite the existence of bureaucratic incentives that promote the effacement of heterogeneity, there are are still different "philosophical universes" even in analytical philosophy. Unlike some folk at NewAPPS, who advocate ongoing cross-fertilization among different philosophical traditions (and/or the sciences), I think it is an open question if more engagement among any two of these leads to more philosophical benefits. All I promote here is suspicion of existing efforts to limit the very possibility of shared inquiry. This is why we need a lot more reviews like Bernstein's.
*It is a bit awkward to call the Lewisian approach the more "traditional" one, given that the powers-based approach can appeal to a very ancient philosophical tradition.