Philosophers as a rule are excellent researchers; they've figured out how to prioritize their research focus to home in on the foundational meaning-of-life issues confronting all humans. This is confirmed at least in part by the foundational place of philosophy in the wikipedia hierarchy. (Would this have ever become clear before the days of hyperlinking? I remember those days; "woke" millennials don't; they have no frame of reference here.)
So let's consider the population of philosophers. A great many are in academia as full-time professionals, some are independent of that milieu.
Among that population there are those who are big on Aristotle and the Aristotelian tradition. Aristotle more or less was the first to perfect a research program (not that Plato was chopped liver). Time and time again Aristotle has reappeared on the history-of-philosophy scene to the great benefit of the participants (as inspiration if nothing else). The recent revival of virtue ethics when before only Kantian and utilitarian ethics dominated the scene is one case in point.
As documented extensively in this blog, there is a by-and-large formidable neo-Aristotelian stream of thought inspired by Ayn Rand. (Now things are starting to get pretty narrowed down.) If there's one central and crucial theme uniting the systems of Aristotle and Rand it is a focus on what I term intellectual perfection(ism). (Narrowing things down further....) The gist of this is that we have an ethical imperative to maximize the actualization of our intellectual potentialities; it is the best organizing principle available for better living. And while philosophers almost to a person (I leave out pseudo-philosophers who are more like sophists) value the principle of intellectual perfection or integrity or wholeness, Aristotle and Rand are among the few to make this into an explicit defining principle of living well. It's not just the actualization of just any set of potentials that makes for self-actualization or eudaimonia; at the foundation, center and peak expression, there is intellectual activity tending toward perfection.
Then there are those Aristotelians and Randians who are obsessively into methodological perfection(ism); the term "dialectic" comes up in connection with Aristotle and his comprehensive and sprawling research program; it's about tying together all the strands in an organized unity. In connection with Rand the terms/concepts "context-keeping" and "integration" cover more or less the same methodological territory. So we've more or less narrowed things down to Sciabarra (editor of the Journal of Ayn Rand Studies) and his circle of associates as far as "dialectic" goes, and to Peikoff (Rand's hand-picked heir) and his circle as far as integration/context-keeping go. But there's almost no overlap between these two groups; it is as though they exist in a condition of dialectical alienation or tension. (As to why that is, well. Long-ish story.)
As far as self-actualization or eudaimonist ethics goes, there is a subset of Aristotelian-Randians who specialize in ethics and who picked up on the themes of Norton's Personal Destinies. This includes "Dougs" Den Uyl and Rasmussen and Tibor Machan, but not all that many others. Norton integrates themes from classical eudaimonism (namely Plato and Aristotle) with modern humanistic psychology (Jung and Maslow). I've only read some of Jung and Maslow; somehow the intellectual-perfectionism theme in Aristotle and Rand covers the widest explanatory range of the content and appeal of eudaimonism in its strongest form. Anyway, Sciabarra - in the circle of associates with the "Dougs" and Machan - cites a massive number of sources informing his Total Freedom: Toward a Dialectical Libertarianism (2000), but Norton isn't among them. I guess he isn't the specializer in ethical theory that the "Dougs" and Machan are? So we encounter yet another division of sorts, resulting from a diversification of specialized knowledge. So an avid researcher would have to home in on the most significant sources/figures cited in Total Freedom (hint: Mises, Hayek, Rand) as well as, say, Machan's Individuals and Their Rights (1989) and the "Dougs" Philosophic Thought of Ayn Rand (1984) and Liberty and Nature: An Aristotelian Defense of Liberal Order (1991), to both have promising leads to Norton as well as to conjure up whatever connections Norton might have to Sciabarra's dialectical-libertarian thesis. Along the way, such a researcher will most likely have encountered the libertarian rights theory of Eric Mack and drew meticulous comparisons/contrasts to these others' rights theories. Further along the way, one may have encountered the 1974 volume edited by Machan, The Libertarian Alternative, which contains John Hospers' "What Libertarianism Is," which contains a memorable knock-down formulation of the synoptic libertarian norm: "other men's lives are not yours to dispose of."
The number of people who would have engaged in the research covering these works (which have already integrated a lot of source material themselves, so hopefully nothing big got overlooked in the lines of transmission), is probably quite small. But it is, in terms of foundational importance and tradition worked in, probably the most high-efficiency philosophical research to be done. Does anyone really do better work than the Dougs, explicit and avowed perfectionists? Norton also uses the term "perfectionism" as more or less interchangeably with "edaimonism," "self-actualization ethics," and "normative individualism." But he doesn't get into the more distinctively Aristotelian-Randian-style emphasis on intellectual perfection(ism).
I mention in connection with Aristotle the notion of an organized unity. Nozick, who has a sprawling research program of his own (he probably had a lot more raw smarts than I do), spoke of value in terms of organic unity, and more specifically an organic unity made up of two criteria: (1) the range, scope, or quantity of material being organized, and (2) the "tightness" of the unity or organization. (Philosophical Explanations (1981) and The Examined Life (1989).) Somehow Nozick manages (I'm not clear as to how, exactly) to keep this conception of value separate from his idea of "flourishing" which he takes to be inadequate as a unifying theme in ethics. Given what I've been saying so far, I think there is a most-viable way to unify these, uh, strands. Are "organized life," "integrated life," and "flourishing/eudaimonic life" mapping different territories? I don't see how.
So at this point we have the following figures mentioned: Aristotle, Rand, Peikoff, Sciabarra, the Dougs, Machan, Mack, Norton, Nozick.
Researchers on Aristotle researchers leads one to Oxford's T.H. Irwin, author of Aristotle's First Principles (1988) and the utterly massive The Development of Ethics (2007). Irwin is a good man, and thorough. If one has only so much time on one's hand to study Aristotle and the history of ethics, respectively, Irwin is a good bet. (Irwin is big on the theme of dialectical method in Aristotle, and is cited in Total Freedom.)
Ferrarin ties together the ridiculously abstruse presentation in Hegel's writings with themes central to Aristotle's philosophy of nature and spirit(/soul?), in Hegel and Aristotle (2001). Comparative studies between Aristotle and other towering figures in the history of philosophy include Aristotle, Kant and the Stoics (Engstrom and Whiting, eds., 1996) and The Highest Good in Aristotle and Kant (Aufderheide and Bader, 2015). Leading Kant scholar Christine Korsgaard draws comparisons between Kant's conception of acting for the sake of duty and Aristotle's acting for the sake of the noble (to kalon), in a comparative essay in Creating the Kingdom of Ends (1996) (or is that a reprint from the Engstrom and Whiting collection?). [Edit: Also, Kant and Aristotle: Epistemology, Logic, Method (Sgarbi, 2016), which I was all over like flies on shit almost the moment it was published...] [Edit: Also, Making a Necessity of Virtue: Aristotle and Kant on Virtue (Sherman, 1997).]
The concept of to kalon may not be limited just to the noble, but also the fine or beautiful, suggesting an aesthetic component to goodness. On the subject of the noble, specifically, Nietzsche in Beyond Good and Evil (section 287) speaks of the noble soul having reverence for itself. Not only is this mentioned by Rand in the 25th anniversary edition of The Fountainhead, but the Kaufmann translation of Nietzsche refers to Aristotle on the great-souled man as a proper lover of self. It's like the strands just keep tying together. I'm aware of (but have not yet read) Alexander Nehamas's well-regarded Nietzsche: Life as Literature from the '80s, but the title suggests an aesthetic conception of a desirable or choiceworthy life (although I'm not really clear at this point on how the concepts of "desirable" and "choiceworthy" fit in with Nietzsche's metaethical scheme). In any case, these points need to be properly integrated and/or differentiated with the aformentioned theme in Nozick about organic unity and how aesthetic value specifically fits into that.
So we have a research program that includes so far: Aristotle, Rand, Peikoff, Sciabarra, the Dougs, Machan, Mack, Norton, Nozick, Irwin, Ferrarin, Korsgaard, Nietzsche, Nehamas.
The folks who've gone through the Peikoff courses thoroughly to the point of automatization/habituation of the prescriptions therein, by and large have it together pretty well. But I part ways with that crowd mainly on matters of the proper approach to "philosophical" polemics, such as their Kant-bashing. An effort to keep full context as prescribed in the Peikoff courses leads me to making a full effort to understand those philosophers as well as, . . . well, as well as Rand wanted her own ideas to be understood before critiqued or commented on.
Then there's Alan Gewirth's Self-Fulfillment (1998), a culmination of a long lifetime of ethical thought. I was kind of disappointed that Norton receives such cursory treatment there, but Gewirth is also integrating a ton of other material as well. As is an increasingly common occurrence in ethical theory these days, Gewirth synthesizes 'Aristotelian' teleology and 'Kantian' deontology. Mack was doing this back in the '70s with his 'Egoism and Rights' dissertation/article.
And then there's researcher extraordinaire, Mortimer J. Adler, the main organizer of the Great Books series (millennials know all about that, right?), and author/compiler of two massive books: Great Ideas: A Lexicon of Western Thought and Great Treasury of Western Thought (co-edited with Charles van Doren of Quiz Show notoriety, of all people?). I've only gotten through some parts of the Treasury but made it all the way through the Lexicon, which was quite edifying.
A great many of these items/authors seem to me to be essential parts of a top-notch philosophical research program. Other books that strike me as essential (but which I have not yet gotten to) include: Bernard Williams, Ethics and the Limits of Philosophy (1985); Nussbaum, The Fragility of Goodness (1986); S.L. Hurley, Natural Reasons (1989); and Parfit's major works, Reasons and Persons (1984) and On What Matters (2010 and later). Also on any avid lifelong learner's bookshelf should be volumes of writings by Franklin, Washington, Jefferson and Lincoln. We're talking bare essentials here, now; if you have room for Thomas Paine he should be included.
I have among my "essentials" in hard copy format (in addition to gobs of books in e-format...) a 2001 or so volume titled Moral Knowledge (ed. Miller, Paul and Paul 2001), a collection on metaethics. Metaethics is a difficult genre; I have not yet gotten more than a few pages in that volume.
Back when I was an obsessive/completist/perfectionistic student of Econ before transferring that obsession to philosophy research (mainly due to Rand), I homed in on a particular volume titled A History of Economic Theory and Method (Ekelund and Hebert). I've since supplemented that with Intellectual Capital: Forty Years of the Nobel Prize in Economics (Karier, 2010). And I still have a nice volume, Austrian Economics: A Reader (Ebeling, ed., 1991-ish) which I must have discovered in a Laissez Faire Books catalog.
The Oxford Handbooks series is also a very useful, state of the art, highest-tier-university-press learning resource. (There's even an Oxford Handbook of Lifelong Learning. How soon do I get to it? Before or after the Cambridge History of Capitalism? Before or after Sciabarra-mentor Ollman on alienation and dialectical method? Before or after the Oxford Handbook of Virtue? And does the section on epistemic virtue therein draw close connections/integrations to intellectual perfectionism? Does LeBar's essay on (virtue-)eudaimonism in this volume serve as an adequate condensation of sorts of his The Value of Living Well [2013]?) One could keep busy with just this Handbooks series for a very long time.
One George F. Kennan condensed/essentialized a long lifetime of learning into his book, Around the Cragged Hill: A Personal and Political Philosophy (1993), which I happened upon in a used book store. When do I get around to it? Somehow I've already been pulled into reading another book found at the same store, Talents & Geniuses by Gilbert Highet; a nice read, certainly easier to get through than a metaethics text, say.
Dennett is a thorough researcher - somehow only he revived Rapoport's Rules, in Intuition Pumps? - but most of his books I've tried I made about halfway through before moving on to other things; his research priorities have him focused on other things, and that's cool.
Given constraints on time and cognitive powers, one needs to essentialize/condense as much as possible. The above resources seem to be what best survive the process of sifting and a modest book budget. This principle also applies to research in music and film. There are some films I can quote nearly back to front. Essential filmmakers include Kubrick, Tarkovsky, and Welles as tippy-top tier. Do enough back-to-front sifting and re-sifting in major American team sports statistics, and you might develop some serious knowledge there as well. I'm not saying I'm anywhere near Bill James' league as baseball researcher, but at least I've read James fairly indepth. Millennials wouldn't remember that On-Base Plus Slugging (OPS), a simple but really good measure of batting prowess, was once called Production and included in the Total Baseball encyclopedia.
As indicated in the post title, this was a narrowing down of some kind. Who on this planet has engaged in the research necessary to be able to list and discuss all these things above? Not very many people. In fact, it might be only one person. We might, if so inclined, bring in Leibniz's famous principle of the identity of indiscernables to identify that person. (How soon do I get to the Oxford Handbook of Leibniz?) The one and the same person who listed and discussed all the things above also turns out to be the person who authored Prologue to an Aristotelian End of History (2015), which far (?) surpasses anything else I'm aware of in terms of the world-historic-important, fundamental essentials integrated into one work. (From a marketing standpoint it's something of a hurdle just to get past the title. Me, I'm all over a book with that sort of title like a fly on shit, of course. And probably the optimal course in this regard is not to invest a lot of time/resources in marketing but in more research front-loading to the point that it's front-loaded af for the next book or series of them.) On top of that, this author has a really thorough approach to blogging (with posts characteristically chock full of supporting/contextualizing links when needed). On top of that, the author has homed in on a 'Better Living Through Philosophy' theme, as though that were perhaps the most perfect theme one could present to a wide reading audience, and where no one else seems to be (explicitly, systematically) taking up the idea quite so obsessively. The progress here looks promising. Can the research be even better prioritized for honing in on the truly most essential?
If the traces a human leaves to posterity are key to what gives meaning to one's life, it's looking okay so far in this instance; it'll look even better if/when Better Living Through Philosophy becomes a final published reality. (Or, to adopt Norton's conceptual scheme, how does this implicit reality become actuality, where an "ought" and an "is" come into unity? And how Hegelian is that conceptual scheme, exactly?) But what comes before and after that final product, research-wise? And how "self-referential" must that text unavoidably be, particularly if it must be placed within the history (and future? and end of history?) of thought?
[something of a precursor post to this one, here]
(What would a fully meticulous narrowing down look like?... Well, darn, I left out Aquinas. Not an expert there. Doug R most likely would most fully know the integrations/differentiations with Rand there. My experience after about 140 pages of Stump's Aquinas (2003) was that it was coming off as distinctively rationalistic - lots of abstract conceptual architecture but hard to tie down to perceptual/concrete experience. Then very shortly thereafter I am re-listening to one of Peikoff's most essential courses where the subject of rationalist polemics comes up, and Aquinas is mentioned right off. Peikoff had made it his mission from Understanding Objectivism (1983) onward to root out rationalism (e.g., 'floating abstraction') in method. Sciabarra identifies both rationalism and empiricism as one-sided/incomplete rather than dialectical, and doesn't include Aquinas among his paradigmatic dialectical thinkers (e.g., Aristotle, Hegel, Marx, Rand). For whatever any of that is worth. Oh, and I did read through most or all of this book, which somehow caught my attention. That, along with the fairly extensive treatment of Aquinas in Irwin's Development of Ethics, is about the extent of my Aquinas study so far. And of course the Oxford Handbook of Aquinas awaits...)