I have contributed to the history and development of twentieth century analytic philosophy as a field, writing on, e.g., the contributions to philosophy of the Vienna Circle, Frege, Russell, Wittgenstein, Gödel, Turing, Austin, Feyerabend, Quine, Rawls, Cavell, Putnam and Kripke. A co-edited volume (with S. Shieh) appeared in 2001, Future Pasts: The Analytic Tradition in Twentieth Century Philosophy (Oxford; online edition 2004), another (co-edited with Alisa Bokulich), Philosophical Explorations of the Legacy of Alan Turing -- Turing 100) will soon appear in the Boston Studies in the Philosophy and History of Science Springer Series, and a third (co-edited with James E. Katz), Philosophy of Emerging Media: Understanding, Appreciation, Application (Oxford, 2016) is a pioneering textbook of readings for PhD coursework in this emerging field. At Boston University I run the Boston Workshop in Early Analytic Philosophy, an informal, ongoing seminar in which experts who are coming through town meet with PhD students and read a workshop paper.
I work primarily in philosophy of logic and mathematics, with additional strong interests in philosophy of language, aesthetics, ethics, and political theory (articles on aspect-perception, Kant, notions of simplicity, and Rawls). I am fascinated with the medium of philosophy, namely language, and specifically with mathematics and logic, but I believe in learning from history, and I don't see the divide between pure argumentation and the settings within which we employ it as a general dichotomy built for all occasions and times. I am also a liberal and pluralistic naturalist who loves to read Emerson and Thoreau, and I count myself a feminist, not by area of specialization but as a philosopher and citizen of the world. Language---part of the world around us, which is constantly evolving---is the place where reasoning, argumentation, and valuable distinctions take on their shape and force. At the heart of the languages of science lie mathematics and logic, which are needed to handle the variety of complexities that arise, and a piecemeal approach without general dichotomies is the one I prefer, one which takes into account how the technology appears to its users. I think 20th century analytic philosophy helps teach us this, because it inaugurated and unfolded the philosophical consequences of the revolution in logic that took place at the end of the 19th century, one lesson of which is that we cannot hope to agree on a single grand theory of truth or meaning across the board, and so require conversation and discussion---philosophy and science and logic---to keep the notions of truth and meaning going. Borders are permeable among all these fields, wandering over, historically and conceptually, to the philosophical and logical foundations of computer science, and to the philosophy of technology.
Archival research into the history of 20th century philosophy has kept me busy. I had the great good fortune to have studied with Ruth Anna Putnam, Owen Flanagan, Ken Winkler, Alister MacIntyre and Ifeanyi Menkiti (at Wellesley College) and Stanley Cavell, Burton Dreben, Hilary Putnam, Jack Rawls, Warren Goldfarb and W.V.O. Quine (at Harvard). I continue to learn from many of their best students to this day. My large study of Russell's significance to Gödel (with A. Kanamori) has just come out, based on Gödel's remarkable MaxPhil notebooks of the early 1940s. My most recent historical work concerns the dark era of logic in the 1910's and 1920s in the USA (Sheffer, C.I. Lewis, Post). A box of Sheffer's papers wound up in my basement, containing the only extant copy of notes of Bertrand Russell's 1910 Cambridge Lectures, notes of seminars by Royce, William James, and others, and signed offprints by Frege, whom Sheffer visited (along with Peano, Burali-Forti, and others) in 1911. Though Russell praised Sheffer's new logic program in the 2nd ed. of Principia Mathematica, no one has really understood what it was or why he undertook it. Yet it anticipated Tarski's later account of logicality by 60 years, and had an impact, not only on logicians like C.H. Langford, but philosophers like Susanne K. Langer, on whom I'm also working now. Russell urged his first readers to wholly rewrite Principia Mathematica, and we see in the 1920s the first steps toward the development of wholly different traditions within logic that still shape ongoing work.
Recent philosophical essays of mine offer analyses of logician/philosophers such as Gödel, Turing, Hao Wang and Rohit Parikh, each (incidentally) influenced by Wittgenstein and each having made serious contributions to philosophy and computer science, as well as pure logic and mathematics. The writing for which I'm probably best known is on Wittgenstein's philosophy of logic and mathematics, which I think ought to be taken very seriously, not only for understanding him and his place in 20th century philosophy, but also for understanding the whole issue of the hardness of the logical "must" and how we only make sense of it only against a contingent backdrop of human understandings, actions, and mutually recognizable interests.
No, I don't think Wittgenstein was right about everything! Instead, his evolution represents an important watermark in the history of philosophy, from a strongly top-down, grand theory approach to a more complex, piecemeal, step-by-step approach in which the issues of what individuals do, what they say, and how things appear to them---something that after all evolves---must be taken into account and discussed as we go, all the while holding on to those primordial distinctions between right and wrong, true and false, that we need to make sense of and interpret things. As I understand Wittgenstein, he thought that philosophy of this kind was just beginning, and we ought to attend to developing it; I do not think he was an "end of philosophy" philosopher, or a "quietist", "formalist", "finitist" or "social constructivist". Much less did he show that all philosophical problems concern language alone. Instead, logic was the heart of it: he injected the piecemeal user-end approach of drawing distinctions locally, in light of what we share, in an open-ended way, into the heart of European and American philosophy mid-century, a reasonable naturalism akin to the best in Quine and Putnam. I take this to have been a sensible turn in the history of philosophy, one that bequeathed to us many challenges and the need for a lot of philosophical discussion. Wittgenstein's philosophy has "legs" in the sense that a huge variety of traditions have attempted to learn from what he did: a good thing, because we don't want just to do what he did, but to go beyond it. As some recent papers of mine show, he influenced and was influenced by Alan Turing, in sensibility and philosophical outlook: not an inconsiderable thing, given Turing's importance to the world we live in today.
Lately I've become focussed on the issue of "aspect-perception", the experience of turning from one way of seeing things to another. This kind of experience is not, I think, very well understood, though it's central to philosophy in every tradition and not well understood in present day philosophy of language and mind. I think it raises fundamental questions about how we are best to dance with distinctions between meaning and understanding, logic and psychology, history and philosophy, ontology and epistemology, value neutrality and normativity. As I learn from philosophers of feminism and those thinking through issues of race, I think the notion should be developed and applied. There are phenomena of depth, acquaintance, and understanding that philosophers need to be able to recognize and discuss, be these in matters of human suffering, aesthetic experience, or mathematics. Flattening out---the reduction of a person to a number, of a proof to a sequence of formal objects, of a social network to an algorithm, of mathematics to a fiction, and so on---occur throughout everyday life and in philosophy itself, seemingly more and more. For me, the notion of an aspect plays a logical role, and I am interested in how, e.g., the grammar of the "as" phrase works. No linguist has offered a general theory of it, but it is central to much philosophy and to how we talk in and about logic and mathematics, as well as to how we demarcate and discuss selves and their social roles. My current PhD student, Vaughn Cartwright, is writing a fascinating dissertation on the syntax and semantics of the "as" phrase.
My current manuscript offers a reconstruction of philosophy's role in the work of Gödel, Wittgenstein and Turing: they argued with one another about the significance of undecideability and incompleteness and were aware of the choices about relations among logic, truth, and meaning that each made. I am also co-authoring a book with Felix Mühlhölzer, Wittgenstein's Annotations to G.H. Hardy's A Course of Pure Mathematics: Wittgenstein's Non-extensionalist Understanding of the Real Numbers. Articles on logic in the 1920s (Sheffer, Susanne K. Langer) and novelty and modernism are under way. I'm back most recently to thinking about W.V.O. Quine's naturalism and pragmatism, and how they manage to keep shaping debates in philosophy to this day.
In an age Cornel West has called "post-analytic" and pragmatic, I welcome the opening up of the history and development of twentieth century philosophy and logic to include a more diverse range of people, subjects, traditions, themes, and angles. To understand the nature and limitations of philosophy in the twentieth century we will need, in particular, to take on some of the historical and philosophical themes that my Boston University Colleague Walter Earl Fluker has aptly discussed in his Ethical Leadership: The Quest for Character, Civility and Community (Fortress Press, Minneapolis, 2009).