Sunday, January 31, 2010

NDPR Paul J. Weithman (ed.), Liberal Faith: Essays in Honor of Philip Quinn

Notre Dame Philosophical Reviews

2010-02-01 : View this Review Online : View Other NDPR Reviews

Paul J. Weithman (ed.), Liberal Faith: Essays in Honor of Philip Quinn, U. of Notre Dame Press, 2008, 216pp., $40.00 (hbk), ISBN 9780268044169.

Reviewed by Ted Poston, University of South Alabama

 

Liberal Faith is a collection of essays organized around Philip Quinn's research interests, in particular Quinn's interest in working out his Christian faith within a commitment to a broadly liberal agenda. The book includes papers in epistemology (by Linda Zagzebski and Richard Foley), philosophy of religion (by Eleonore Stump and Paul J. Griffiths), and political philosophy (by Robert Audi, Paul J. Weithman, and Sumner B. Twiss). Weithman provides a helpful introduction that summarizes each paper and connects the papers with themes from Quinn's research. In addition, Weithman includes a touching eulogy for Quinn at the end of the volume. In view of Weithman's useful summary of the papers, I will forgo another summary and instead focus on a few of the papers that stood out. I end with an extended discussion of Eleonore Stump's superb contribution "Presence and Omnipresence".

Liberal Faith is a fine tribute to an excellent philosopher. As the diverse nature of the essays reveal, Philip Quinn had a remarkable range of interests in philosophy. What is more notable is Quinn's ability to write on these topics with the upmost clarity and sensitivity to the fundamental issues. A hallmark of Quinn's scholarship is his facility to wield the tools of analytic philosophy while also revealing a depth of liberal arts knowledge. Liberal Faith honors Quinn's memory in this respect by bringing together a group of first-rate philosophers to work on the issues Quinn cared deeply about. Paul Weithman is to be thanked for bringing together this collection of essays.

Linda Zagzebski's paper, "Self-Trust and the Diversity of Religions", presents a novel take on the problem of religious diversity. Building on Richard Foley's work on intellectual self-trust, Zagzebski argues that we must also trust our emotions. In particular, if we admire an adherent from a different religious tradition, self-trust commits us to trusting our respect for that person. As Zagzebski presents it, this admiration involves the thought that if I had grown up in a different context I would imitate this person. This strengthens the problem of religious diversity by including a deep respect for saints from other traditions which provides a window through which we may see an alternative self.

It is unclear exactly what to make of this added dimension to the problem of religious diversity. Readers of Herman Hesse's Siddharta are often moved by his allegorical tale of the young Buddha as I was when I first read it. I still continue to have a deep admiration for Siddharta and I recognize that if I grew up in a different tradition I would imitate Siddharta. But so what? How does this undermine my evidence that the central claims of Christianity are true? Perhaps Zagzebski's point is just to undermine a certain brand of exclusivism on which the moral virtues are exclusive to a particular religious tradition. But excepting this implausible form of exclusivism, it's not clear how Zagzebki's emphasis on the role of emotions strengthens the problem of religious diversity.

Paul J. Griffiths paper "Self-Annihilation or Damnation?" provides a fascinating study of traditional Christian views on the final state of persons. Griffiths observes that by the fourth century, Christian eschatology could easily yield the result that people can annihilate themselves, i.e., completely remove themselves from existence by ceasing to participate in the divine life. Griffiths notes, though, that both Augustine and Aquinas explicitly and yet unsatisfactorily resist this implication. Griffiths ends by sketching a view of annihilation that coheres with this earlier eschatological tradition. Fans of C.S. Lewis's The Great Divorce will find Griffiths' essay a welcome exploration of the kind of eschatology Lewis imaginatively portrays. Like Lewis, Griffiths suggests that persons can gradually remove themselves from participating in divine life and so literally come to nothing. Griffiths observes that this frightening possibility helps to remove the objection that annihilationist views fail to uphold the moral seriousness of human sin.

Robert Audi's essay, "Moral Foundations of Liberal Democracy, Secular Reasons, and Liberal Neutrality toward the Good", aims to provide a moral grounding for a liberal democracy and, also, to evaluate the extent to which this grounding supports a substantive conception of the good. Audi argues that an intuitionist approach can provide an adequate grounding for liberal democracy, and further that this grounding can support a substantive view of human flourishing. Audi's intuitionist approach supports what he calls "the principle of secular rationale" according to which "citizens have a prima facie obligation not to advocate or support any law or public policy that restricts human conduct, unless they have, and are willing to offer, adequate secular reason for this advocacy or support" (p. 139). My concerns with this principle are similar to one's voiced by Phil Quinn in his paper "Political Liberalisms and Their Exclusions of the Religious". To mention just one issue, there is likely to be no agreement on what counts as a secular rationale and so the exclusion of religious reasons smacks of unfairness (see Weithman's introduction pp. 18-20 for a discussion of this issue).

In his introduction Weithman observes that contributors to a commemorative volume like this "are supposed to honor Phil by putting their talents to work advancing discussion of a representative sample of the questions he cared about" (p. 2). Eleonore Stump's contribution, "Presence and Omnipresence", exemplifies this goal. Her aim in this paper is to explore the nature of union with a beloved friend such as the friendship between Sam and Frodo in JRR Tolkien's The Lord of the Rings. Stump's paper admirably succeeds in bringing to light a host of issues connected with this topic.

Stump's paper is rich and deserves a close reading. She begins by observing that "union between friends requires mutual closeness and personal presence" (p. 60). This union is not achieved merely by being in the other's presence. This observation leads Stump to distinguish between minimal personal presence and significant personal presence (see p. 61). Minimal personal presence can be achieved simply by being in the same room as another person and it doesn't involve closeness between persons. A more valuable form of personal presence is significant personal presence. This, she says, is "a particularly significant or powerful way of being close to a person" (p. 62). This kind of presence is lacking when a person is "distracted all through dinner and . . . [is] never really present to me" (p. 61).

Stump then proceeds to criticize an earlier account of personal presence that she developed with Norman Kretzmann. On that account one person is present to another if "they have direct and unmediated causal contact with and cognitive access to another" (p. 62). Direct and unmediated causal contact requires only that the contact "does not have as an intermediate step the agency of another person" (p. 62). Stump thinks this account "misses something even in the minimal sense of personal presence" because the account falsely implies that, e.g., Zeus would be present to the scene of the Greek and Trojan War when he is having dinner in Ethiopia (p. 62, 63). More importantly, this account is even more inadequate for understanding the nature of significant personal presence.

To improve upon her and Kretzmann's earlier account of presence, Stump claims that significant personal presence requires both second-person experience and joint or shared attention. What is second-person experience? Stump explains:

One person Paula has a second-person experience of another person Jerome only if (1) Paula is conscious of Jerome as a person; (2) in being conscious of Jerome as a person, Paula has direct and unmediated cognitive access to Jerome and is in a position to have direct and unmediated causal contact with him; and (3) Jerome is conscious (p. 63).

Assuming that cognitive contact is a kind of causal contact and that direct and unmediated cognitive access to J requires that J is conscious, we can express this necessary condition for second-person experience more succinctly as follows: P has second-person experience of J only if in P's being conscious of J as a person, P has direct and unmediated cognitive access to J. On Stump's view second-person experience doesn't require direct sensory contact with another person. For example, Paula can have a second-person experience of Jerome through email exchanges (see p. 64 and fn 11 on p. 78). An interesting question is whether one individual can have a second-person experience of a historical figure. Does second-person experience of another require that the other exists (see fns 12 and 13, pp. 78-9)?

Second-person experience, though, isn't sufficient for significant personal experience. For that kind of personal presence, joint or shared attention is required as well. Stump discusses joint attention via recent studies on autism. Though joint attention is difficult to describe, it is clearly missing in some autistic children. She quotes Peter Hobson as saying that joint awareness requires

[that one] needs to be aware of the object of event as the focus of the other person's attention -- and in addition, for full 'jointness,' he or she should share awareness of the sharing of the focus, something that often entails sharing an attitude towards the thing or event in question (quoted on p. 66).

Stump calls our attention to a more fundamental form of joint attention: dyadic joint attention or dyadic shared attention (p. 67). One puzzle for researchers on autism is that while autistic children are capable of joint attention they don't engage in dyadic attention. Stump claims that part of the answer has to do "with the fact that there is voluntary control of attention" (p. 67). She thinks that dyadic shared attention has a special role to play in significant personal presence. Shared attention requires mutual awareness of another which involves awareness of the other's awareness of you and further even awareness of this. Shared attention, thus, is like common knowledge.

The last stage in Stump's analysis of the nature of union between beloved friends is an investigation on closeness. She begins by observing that shared attention is maximally rich when there is a relation of mutual closeness between the persons (p. 69). What is this relation of mutual closeness? It is difficult to say. Stump observes that propinquity is not sufficient for mutual closeness and, further, adding lively conservation and general benevolence to physical proximity doesn't suffice for mutual closeness. This is because all three may be present even though the participants are radically isolated from each other (see p. 71).

What then can be said about closeness? Stump contends that closeness requires the other person's willingness to share significant thoughts and feelings. For Paula to be close to Jerome it requires that Jerome is willing to share significant thoughts and feelings with her (p. 71). Paula can't be close to Jerome merely by sharing her thoughts and feelings because it requires something on Jerome's part. Both have to be willing to treat the exchange as meaningful. A further part of Stump's characterization of closeness involves the role of the will. Though hard to characterize, closeness requires a desire for the other person along with a vulnerability to the other person (see pp. 72-3). Finally, she observes that closeness requires that a person is not self-alienated (p. 74). Closeness demands that a person is integrated within herself and also that the person is wholehearted (p. 75).

So what is the nature of union between beloved friends? In the final analysis this union requires significant personal presence and mutual closeness. This account carries interesting implications for union with God. Stump observes that God can't be close to an individual alienated from himself (p. 76). Union with God requires a personal integration. An interesting variant on this implication is the Augustinian claim that the kind of personal integration necessary for union with God may require God's grace. In this case, if an individual is to enter into union with God it requires the divine grace to restore a person to wholeness.

Another implication of Stump's account for union with God is that, according to her, "the only thing decisive for the kind of personal presence, significant or minimal, that an omnipresent God has to a human person is thus the state and condition of the human person himself" (p. 76). Again She writes, "if Paula wants God to be significantly present to her, the establishment of the relationship she wants depends only on her, on her single-mindedly and wholeheartedly wanting that relationship" (p. 76). But this claim doesn't seem right. Theists have attested to the dark night of the soul in which God removes his comforting presence for a time. The book of Psalms is replete with references to God hiding his face (e.g., Ps 13:1; Ps 22:2; Ps 30:7). It appears, therefore, that God has the ability to withdraw his presence for a time, even though people may do what they can to enter into such a relationship. Furthermore, it is unclear why Stump thinks her analysis implies that significant personal presence with God depends only on the human person himself. Granted, God is minimally present everywhere in Aquinas's sense that God can act anywhere and knows whatever occurs. But to achieve significant personal presence God has to choose to reveal himself in a particularly meaningful way. So, it doesn't appear to be the case that Stump's analysis of omnipresence is committed to this one-way dependence. However, her general analysis of significant personal presence rightly stresses the role of an individual's self-revelation. Self-revelation is risky and with respect to God self-revelation requires searing honesty. To borrow her earlier example of Jerome and Paula, if Jerome is unwilling to reveal his deepest motives and thoughts to Paula, then even if Jerome makes a show at self-revelation, there will be no union between beloved friends. This verdict is especially secure when Paula knows that Jerome's intentions are less than pure. If this judgment fits some relationships between persons, then we have even more reason to think that it fits a relationship with God. Stump is right, therefore, to lay stress on the role of the individual in entering into a significant relationship with God. Overall, her account of the nature of the union with a beloved friend raises a number of fascinating issues. I hope that her contribution will gain the attention it deserves.

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Wednesday, January 27, 2010

NDPR Thomas Wheatland, The Frankfurt School in Exile

Notre Dame Philosophical Reviews

2010-01-27 : View this Review Online : View Other NDPR Reviews

Thomas Wheatland, The Frankfurt School in Exile, U. of Minnesota Press, 2009, 415pp., $39.95 (hbk), ISBN 9780816653676.

Reviewed by Max Pensky, Binghamton University, The State University of New York

 

Following in the footsteps of earlier compendious intellectual histories of the Frankfurt School by Martin Jay and Rolf Wiggershaus, Thomas Wheatland's The Frankfurt School in Exile offers a thorough intellectual, political and institutional history of the adventures of the Frankfurt Institut fuer Sozialforschuung in the United States. Concentrating on this rich and strange institutional odyssey, and tapping the previously ignored archives of the Department of Sociology in Columbia University, Wheatland presents a far more vivid, nuanced, and strange picture of the Frankfurt Institute's American years. Among the many entrenched myths punctured in this book, the most important one to fall is the received view that the key figures of the Institute and their American, primarily New York, academic hosts were mutually indifferent. Just as significantly, however, Wheatland documents that the cadre of New York intellectuals gathered around the so-called 'little journals' of the nascent anti-Stalinist Left also had far more interest in, and were in far closer contact with, the Institute members than the existing historical literature suggests. These findings in general compel a reappraisal of the Institute's New York exile. And though Wheatland himself touches only very lightly on the political implications of this more intense and complex relationship, his history also, inevitably, raises questions about the developments that set both the New York anti-Stalinist Left, and less conspicuously the 'core' members of the Institute, on the path toward variations of neo-conservatism.

The Critical Theory of the Frankfurt School has always been a candidate for an intellectual-historical approach: there is first of all the simple fact of its extraordinarily interesting history, the personal dramas of its eccentric and compelling cast of characters, and of course the extraordinary times in which these men lived and wrote. The intellectual history of the members of the Frankfurt School is indeed the history of twentieth century Europe in microcosm: bourgeois and proletariat, religion and secularism, philosophy and politics, crisis and critique. The intellectual histories of critical theory have surpassed in both number and quality the philosophical analyses. In English or in translation, Jay's classic Dialectical Imagination, and Wiggershaus' The Frankfurt School remain unsurpassed, and untranslated German works by Alex Demirovic and Wolfgang Kraushaar document the political life of the postwar Institute in West Germany in minute detail.

But oddly the American years of Critical Theory remain, if not unresearched, then certainly under-researched and susceptible to caricature. Horkheimer and Adorno, comprising the center of the Frankfurt institute, adeptly shifted both personnel and resources to New York, where an uneasy but productive relationship through most of the 1930s produced much of the Frankfurt School's empirical work on authoritarianism and anti-Semitism. Political prudence and justified fears at American anti-communism in the prewar and wartime years led the critical theorists to adopt an attitude of deep reserve with their American hosts, while personally dismayed at the callow mass culture of the United States, the critical theorists nevertheless slogged through their fifteen-year exile in New York and California. Horkheimer and Adorno returned to post-war Germany as the rubble was barely cool, while Marcuse, at Santa Cruz, transformed himself into a Hawaiian-shirted guru of the American New Left.

Well, not quite, as Wheatland's historical research shows in a series of linked studies of the myths and half-truths that this received view is based on. This research turns up no smoking guns or shocking disclosures. But it does considerably complicate and expand our understanding of what happened to the Frankfurt School in New York and California, and this expanded understanding will make it difficult for some of the myths of the received view to survive much longer.

The flight of the Institute's members to New York, and to the leafy enclave of Columbia University and its own building in Morningside Heights, turns out to have been far more slapdash, improvised and compromised than the familiar version records, and was based on deep misunderstandings and disappointments on both sides. With the genuinely risky decision to approve of an affiliation with the Institute, the Sociology Department at Columbia University (or at least a voting majority) thought it was acquiring a well-heeled clique of progressively-minded theorists, sporting both a solid background in European philosophy and a competency in the latest quantitative methods, who could boost the Department's profile at little cost. The critical theorists, for their part, remained willfully ignorant of the ferocious academic politics of the Department just as they did of American academic life in general, often woefully overestimating their own clout. With the exception of Erich Fromm -- a figure whose relation to the "core" Frankfurt School deserves a book-length treatment in its own right -- the members' half-hearted, conflicted, and often painfully inept efforts to integrate themselves with their American colleagues led to just the comprehensive failure one would have expected.

This failure -- the inability of Institute members to adopt, or be adopted by, American culture and society generally and the academic culture of mid-century American social theory in particular -- is once again a more complicated and stranger story now. While it is true that "the institute" walled itself off strategically from many of its American colleagues under fears of a backlash of wartime anti-communism, Wheatland reveals, depressingly, how much this reserve was also a product of Horkheimer's own deeply unattractive will to exert personal influence over a group that was already deeply personally and professionally fragmented well before its American exile. His vindictive reactions to Fromm's far more successful integration into both New York intellectual society and Columbia's sociology department were ill-concealed and ill-considered fits of professional jealousy; their result was a fiasco.

At the same time, Wheatland also documents the counter-narrative to the received view of the Institute's splendid isolation in Morningside Heights. The "Horkheimer circle" (an unfortunate misnomer, in my view) in fact maintained consistent and often substantive interactions with the broader intellectual life of New York in the late 1930s and through the war years, beyond their often inept efforts at academic integration with Columbia. Most notably, there were important cross-fertilizations between institute members and the emergent anti-Soviet left of the so-called little journals: the ground zero, in other words, of American neo-conservatism. Wheatland devotes an entire chapter to the complex pas de deux between the institute and Sidney Hook, and it makes for fascinating reading. As for the rest of the New York public intellectuals of the period -- from Burnham, Howe and Macdonald to younger figures like Daniel Bell and Nathan Glazer -- Wheatland records a history of, for the most part, missed opportunities for substantive and creative exchange, subsisting together with rather intensive and not always unsympathetic mutual interest. The two camps indeed had very much in common, as Wheatland shows, and his account of the parallel developments of critiques of mass culture in Horkheimer's and Adorno's work leading up to Dialectic of Enlightenment, and the (at that point still) leftist-inflected rejection of mass culture amongst the editorial staffs at Partisan Review and Commentary makes for fascinating reading. And yet these parallel tracks, even as Wheatland documents the numerous sidelong glances the two groups constantly exchanged, did not converge in any productive sense. While the anti-Soviet left transmogrified during the Cold War into the intellectual and ideological foundation of American neo-conservatism, Horkheimer and Adorno went on, in the new Federal Republic of Germany, to contribute their own deeply ambivalent political and ideological legacy, serving simultaneously both as living links to a tradition of politically engaged leftist critique in opposition to resurgent right-wing thought in the 1950s and 1960s, as well as staunch anti-Soviet (and anti-student movement) authority figures. Wheatland's book does not venture very far down the path of explaining how or even whether Horkheimer's and Adorno's New York sojourn among the founding fathers of American neo-conservative thought had a measurable effect on their own political journey in the post-war decades. And indeed that would be beyond the remit of this book. But together with the documentation in some of the earlier intellectual histories, there are now far more dots to connect.

Given the revised version of the Institute's American sojourn that emerges from Wheatland's research, it's tempting to adopt a very 'deflationary' account of Critical Theory in Exile indeed. The institutional and methodological innovations that Horkheimer had proposed at the beginning of the 1930s can easily appear as promissory notes that were never ultimately fulfilled; indeed it's tempting to take the Institute's American years as a synecdoche for its larger failings. While Wheatland is too tactful to belabor the point, Horkheimer especially appears in this history as a profound disappointment as both an intellect and a leader: as a martinet and bully, motivated by jealousy and resentment as often as by the Institute's interests, and lacking both the personal qualities and the professional training to exercise competent leadership.

And yet Wheatland's revised, largely deflationary account of the Institute's (and Horkheimer's) many failures and missed opportunities still allows us to see, indeed perhaps allows us to see more clearly, the remarkable aspect of its accomplishments, since despite the enormous obstacles the Institute encountered -- many self-imposed -- the years of American exile were not just a series of disappointments and dissolution but of remarkable creative accomplishments as well. At the heart of these surely is the five-volume Studies in Prejudice, which, for all its balky history and methodological shortcomings, was recognized as a landmark in normatively oriented, empirically driven sociology on its publication in 1950, and remains deeply influential. Even if Horkheimer and Adorno's return to Germany led them to back philosophy rather than sociology, the re-established Institute continued to produce politically committed, empirically grounded sociology throughout the history of the Bonn Republic.

Wheatland's study concludes with a fascinating and troubling re-telling of the received view of Herbert Marcuse's status as -- the word is inevitable -- guru of the New Left. Here the documentation is far more spotty, consisting less of archival evidence than what is missing from the historical archive: any compelling evidence that would suggest that the work on which Marcuse's guru-status is chiefly grounded, One Dimensional Man, was actually read by, and influenced, the New Left's members. Of course it's impossible to prove a historical negative, and it's possible that the book's impact was more subtle and pervasive than not. But Wheatland's argument, supported chiefly by reminiscences by Marcuse himself, suggests strongly that Marcuse's role as chief intellectual godfather of the New Left gets things seriously backwards. As Wheatland argues, it makes more sense to see the New Left's influence on the trajectory of Marcuse's own thought than to trace the overt influences of his philosophy on the self-understanding of the student movement, which seems to have adopted him as a sort of mascot more than turned to him as a source of philosophical direction and self-understanding.

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Tuesday, January 26, 2010

NDPR Franz Huber, Christoph Schmidt-Petri (eds.), Degrees of Belief

Notre Dame Philosophical Reviews

2010-01-26 : View this Review Online : View Other NDPR Reviews

Franz Huber and Christoph Schmidt-Petri (eds.), Degrees of Belief, Springer, 2009, 354pp., $27.95 (pbk), ISBN 9789048137183.

Reviewed by Horacio Arlo-Costa, Carnegie Mellon University

 

This collection focuses on the laws that degrees of belief should obey (Part II), as well as the relationship between degrees of belief and qualitative notions of belief like plain or full belief (Part I), concluding with two articles that deploy logical techniques to articulate the notion of levels of belief (Part III). An essay by Franz Huber introduces the collection. The book covers a significant amount of ground both philosophically and formally. The first and second parts are concerned in part with the tenability and scope of contemporary forms of probabilism in epistemology: a version of Bayesian epistemology for which partial beliefs, or credences, play the leading foundational role (instead of full beliefs and an epistemology articulated by the two Jamesian commands: Believe the truth! Avoid error!).

Some authors from Part II seem to endorse a radical form of probabilism of the sort that Richard Jeffrey defends in various important papers (Jim Joyce seems to be an example). This view amounts to a form of eliminativism according to which the traditional notions of qualitative belief play no role in a mature epistemology of a Bayesian variety. None of the three authors in Part I seem to endorse this view. On the contrary, each seems to think that the traditional forms of qualitative belief play a crucial role in Bayesian epistemology.

The first two authors from Part I (Richard Foley and James Hawthorne) investigate acceptance rules articulated in terms of high probability. Of course, this leads to a view of belief that rejects closure under conjunction. Foley offers philosophical arguments for this view, and Hawthorne characterizes a logic of belief along similar lines. These two articles accordingly defend an epistemological position first proposed and articulated by Henry Kyburg in a series of writings.

Foley seems to assume that the only alternative to embracing a notion of belief that rejects closure under conjunction is the type of eliminative and radical probabilism mentioned above. In the last part of his article, he offers various arguments against this form of radical probabilism. One such argument proceeds as follows:

We sometimes welcome and even demand probabilities, but even here, the probabilities are arrived at against a backdrop of black-and-white assumptions -- that is, a backdrop of belief (p. 46).

This idea can be understood in several different ways. Kyburg would understand it in a way that seems close to what Foley suggests; namely, that the beliefs in the background are themselves obtained in terms of high probability. But Foley observes that the particular beliefs (that the die whose probability of landing on a six I just estimated is not weighted; that the deck of cards used to estimate the probability of drawing a heart is a standard deck, etc.) are so close to being certainties that the question of their probability does not seem to arise.

It is important to see that one can view these certainties as primitively given, thereby abandoning probabilism. After all, this has been the view of one of the founders of Bayesian epistemology: Bruno de Finetti cannot be seen (perhaps surprisingly for many) as a probabilist. De Finetti had a view according to which a qualitative notion of certainty is assumed as an epistemological primitive alongside the notion of probability. Moreover, the notion of certainty plays a crucial role in his characterization of probability. This is the view that he proposes in his Theory of Probability, Volume I (de Finetti, 1990):

Thinking of a subset of truths as given (knowing, for instance, that certain facts are true, certain quantities have given values, or values between certain limits, certain shapes, bodies or graphs of given phenomena enjoy certain properties, and so on), we will be able to ascertain which conclusions, among those of interest, will turn out to be -- on the basis of the data -- either certain (certainly true), or impossible (certainly false), or else possible (p. 25).

What about probability? According to de Finetti, "probability is something that can be distributed over the field of possibility":

Using a visual image, which at a later stage could be taken as an actual representation, we could say that the logic of certainty reveals to us a space in which the range of possibilities is seen in outline, whereas the logic of the probable will fill in this blank outline by considering a mass distributed upon it (p. 25).

This is a perfectly legitimate alternative to probabilism that Foley does not seem to consider in his article. As I explained above, he seems to think that the only alternative to a notion of belief that rejects closure under conjunction is a form of radical probabilism that shuns the notion of belief altogether. Yet de Finetti's articulation of Bayesian epistemology is a clear alternative that relies on two epistemological primitives rather than one. This is a form of epistemological pluralism that apparently is not considered in Part I of this book. According to this pluralistic view, one can adopt a doxastic primitive that is well behaved logically and that therefore is indeed closed under conjunction. Moreover, this underlying notion of belief plays a crucial role in determining what is possible, i.e., which propositions will be considered as probability carriers. In other words, it determines the field over which probability is defined. In philosophy, Isaac Levi has defended this view in a series of writings (Levi, 1983).

Notice that if we adopt the form of probabilism Foley proposes (which Hawthorne also tacitly assumes), then apparently it is impossible to define a notion of full belief closed under conjunction in purely probabilistic terms. Even the notion of certainty would be impossible to capture probabilistically. For consider the obvious option, characterizing certainty as the measure of one's beliefs. As Bas van Fraassen has indicated in his seminal article (van Fraassen, 1995), this characterization of certainty or full belief falls victim to transfinite lottery paradoxes. Consider the mass of the moon reckoned in kilograms. I am sure that it is a number in the real interval [a, b], so if my probability follows Lebesgue measure, the probability that the mass is exactly given by any number x in [a, b] is zero. Hence, my probability equals 100% that the number lies in the set [a, b] – {x}. In other words, the probability that the number is not x for every x in the interval is one, but I am certain (fully believe) that the number is in [a, b].

Thus, the form of probabilism Foley endorses is quite limited. It does not seem capable of representing the traditional notion of full belief. We will see below that there are forms of probabilism that are indeed capable of capturing this notion and which are therefore superior to the form of probabilism Foley accepts. In addition, Foley does not seem to contemplate the possibility of non-probabilist understandings of Bayesian epistemology (like the one proposed by de Finetti), which are also capable of accommodating a well-behaved notion of full belief.

Hawthorne's article is very rich and contains interesting results, but it seems that the same criticism raised against Foley's view can also be raised against his proposal. Hawthorne first develops a notion of qualitative probability (similar to the notion of qualitative probability used by Savage). He defines a binary notion ≥a. The statement A ≥a B can be read in various ways. One of them is: 'a is at least as confident that A as that B.' Another is 'A is at least as plausible for a as is B.' The model is weaker than the usual accounts of qualitative probability. Then certainty is defined as follows: Certa[A] if and only if A ≥a B ∨¬B.

Hawthorne proposes some axioms for ≥a and proves an interesting theorem showing that if Pa is any probability function and we define A ≥a B if and only if Pa[A] ≥ Pa[B], then ≥a satisfies all the proposed axioms. Completeness is also proved: if ≥a satisfies the appropriate axioms, then Pa is unique and A ≥a B if and only if Pa[A] ≥ Pa[B]. So as long ≥a satisfies the appropriate axioms, we have that Certa[A] if and only if Pa[A] = 1, for a uniquely given function Pa.

Now the same criticisms offered above seem to apply here. This notion of certainty is equally victim to transfinite lottery paradoxes. Nevertheless, most of the interesting work presented in Hawthorne's article focuses on defining belief rather than certainty. The corresponding notion of belief is not closed under conjunction. This work is related to fascinating formal work by the author and David Makinson, characterizing the notion of a probability-based conditional determined by threshold probability. This notion is worth studying, but still it seems that this form of probabilism does not manage to make contact with the traditional notions of epistemology (certainty, belief, knowledge). In a way, it changes theme and characterizes a new doxastic notion that is parasitic on the notion of probability.

Is there any form of probabilism immune to the aforementioned problems? Yes. Bas van Fraassen proposes the central idea of a form of probabilism (van Fraassen, 1995). There he introduces the notion of a probability core. According to van Fraassen, a set C is a probability core if the set C and its complement are normal (i.e., if P(.|C) and P(.|U - C) are probability functions), and for each subset B of C and every set D in its complement, P(B|B + D) = 1. Then one can prove that cores are very well behaved. For example they are nested, and if one assumes countable additivity one can show that there is a smallest core (see (Arlo-Costa, 1999)). A slight modification of the theory (proposed in (Arlo-Costa and Parikh, 2005) and (Arlo-Costa, 2001)) guarantees that in the presence of countable additivity and for countable spaces, there is always a smallest core and a largest core. The smallest core has measure one. The proposal is to see the largest core as encoding full beliefs and the smallest core as encoding expectations or "almost certainties." The theory is extendable to the infinite case as well. We can see then that, for example, none of the sets [a, b] - {x} in the example of the mass of the moon constitutes a core (in spite of carrying measure one). But, according to the conception of core offered by Arlo-Costa and Parikh the interval [a, b] is indeed a core (unfortunately according to van Fraassen's original definition of core, there are no cores in this example, something that is also undesirable given that pre-systematically [a, b] seems to encode the strongest full belief of the agent).

This form of probabilism is capable of offering probabilistic characterizations of the traditional notions of full belief and expectation ("almost certainty"). The main idea of the theory is to offer a unified view of degrees of belief and full belief by appealing to a third primitive, the notion of supposition embedded in primitive conditional probability. Still, the price that one pays for this unification is to assume a pre-Kolmogorovian notion of probability. Unfortunately, this form of probabilism (and the notion of primitive conditional probability that it presupposes) is not represented in this volume. Therefore, Franz Huber concludes in the introduction, "subjective probabilities do not give rise to a notion of belief that is consistent and deductively closed" (p. 16). I would qualify this statement: Monadic subjective probabilities do not give rise to such a notion of belief, but dyadic notions of probability do give rise to a notion of full belief that is consistent and deductively closed.

Part I closes with an essay by K. Frankish. The central idea in this essay is also concerned with the derivation of a notion of flat-out belief or full belief from probability. Frankish's essay is very rich. Various other decision theoretic accounts of belief like the one proposed by Maher (Maher, 1993) and Kaplan (Kaplan, 1981) are considered and criticized. Frankish concludes:

the relevant attitude is a commitment to using propositions as a premise in reasoning and decision-making for some purposes in some contexts, regardless of the degree of confidence we have in it. (p. 91-92)

In order for this idea to be precise, one has to explain exactly what it is "to use propositions as a premise in reasoning and decision-making." There are many ways of understanding this proposal. The examples that Frankish presents seem to suggest that propositions of this type can be used to determine, for example, what actions are feasible and what actions are not feasible in a given decision problem. In any case, here we are operating in an area beyond the limits of probabilism. For example, we are supposed to have at hand the rudiments of a decision theory. The previous accounts (including the one in terms of probability cores sketched above) presume that full beliefs carry probability one (although not all events of probability one are full beliefs). Here apparently we can have flat-out beliefs carrying low credence. The account is supposed to be descriptive rather than normative, so it is unclear to what extent the corresponding notion of flat-out belief has its usual normative role.

Part II focuses on the justification of the axioms of the standard notion of probability. It contains as well various articles articulating the notion of degree of belief along different lines than the traditional probability calculus. Standard probability is additive, in the sense that the calculus obeys at least the law of finite additivity (P(A ∪ B) = P(A) + P(B), if A∩B = ∅). Rolf Haeanni's article focuses on belief functions which are super-additive (Bel(A) + Bel(B) ≤ Bel(A∪B), if A∩B = ∅). Haenni presents as well interesting arguments showing how to combine logic and probability in this framework. Didier Dubois and Henri Prade offer a survey of possibility measures which are sub-additive. There is a qualitative possibility theory and a quantitative version of it, the former closely related to non-monotonic reasoning and the latter a special case of upper and lower probabilities (establishing therefore a link with the theory of imprecise probabilities). The article by Dubois and Prade focuses on qualitative possibility theory. The idea is to offer a survey of how partial belief can be represented in possibility theory, and how related issues like acceptance and belief revision can be handled in this setting.

Let ℑ be a field of propositions over a universe W. Then we can define a possibility measure as a function ∏: ℑ →ℜ such that for all propositions A, B in ℑ:

∏(∅) = 0

∏(W) = 1

∏(A∪B) = max{∏(A), ∏(B)}

We can then define the dual necessity measure as a function N: ℑ →ℜ defined for all propositions A in ℑ as follows: N(A) = 1 - ∏(¬A). Alternatively one can define necessity measures as functions N: ℑ →ℜ such that for all propositions A, B in ℑ:

N(∅) = 0

N(W) = 1

N(A∩B) = min{N(A), N(B)}

Now let the necessity measures of possibility theory assign natural instead of real numbers in the unit interval to the various propositions so that ∞ instead of 1 represents maximal necessity. Then the axioms for necessity measures become:

N(∅) = 0

N(W) = ∞

N(A∩B) = min{N(A), N(B)}

Now (as Huber suggests in the introduction) think of the rank of a proposition A as the degree of necessity of its negation ρ(A) = N(¬A). Then we can introduce finitely minimitive ranking functions (studied by Spohn). In fact, these functions are a mere terminological variation of the variant of necessity measures proposed above:

ρ(W) = N(∅) = 0

ρ(∅) = N(W) = ∞

ρ(A∪B) = N(¬A∩¬B) = min{N(¬A), N(¬B)} = min{ρ(A), ρ(B)}

Still the interpretations of both types of functions might diverge. This is not the case when we focus on Shackle's degree of potential surprise (Shackle, 1949, 1969). As both Spohn and Huber explain in their articles, the main interest of ranking functions over and above Shackle's degree of potential surprise and Dubois and Prade's necessity functions is that they offer a nice account of conditional ranking functions (while apparently Shackle struggles with the definition of conditional potential surprise).

Spohn's definition of conditional ranking functions is simple and elegant: the conditional ranking function ρ(.|.): ℑ xℑ → N ∪ {∞} is defined for all A , B in ℑ, with A ≠ ∅ as:

ρ(A|B) = ρ(A∩B) - ρ(A)

The number r(A) represents the degree of disbelief in the proposition A. The additional difference between ranking functions and similarly motivated formalisms is that there are some arguments for ranking functions of the sort offered in probability theory. In fact, there are both pragmatic and non-pragmatic arguments for the thesis that degrees of belief should obey the axioms of the probability calculus. (Some of these arguments are discussed in this volume; see below.) Some arguments of this sort exist for belief functions (Smets, 2002). Such arguments are also available for ranking functions, as the articles of Huber and Spohn explain.

Two main arguments have been advanced for ranking functions. The first is a non-pragmatic argument offered by Huber (Huber, 2007). To appreciate how the argument works, it is useful to notice first that ranking functions give rise to belief sets that are consistent and logically closed. The idea is to define:

Bρ = {A ∈ ℑ: ρ(¬A) > 0} = { A ∈ ℑ: ρ(¬A) > ρ(A)}

The idea of the epistemic argument for ranking functions is that it is epistemically defective to have degrees of disbelief that violate the ranking axioms. Epistemically defective in which way? The argument specifies as a principle of theoretical rationality that it is epistemically defective to have beliefs that are not both consistent and deductively closed. Then the argument appeals to a behavioral specification of degrees of entrenchment and shows that an entrenchment function gives rise to consistent and deductively closed beliefs if and only if it satisfies the ranking axioms. Huber calls this the Consistency Argument.

Huber concludes (Huber, 2007) that

given a link between degrees of disbelief and degrees of entrenchment, the normative force of the Consistency Argument is then proportional to how odd one takes the possibility of knowingly or believingly having beliefs that are not both consistent and deductively closed.

Two observations are relevant here. First, as we noted above, conditional degrees of belief obeying the usual axioms for primitive conditional probability also give rise to consistent and logically closed beliefs (as a matter of fact, one of the consequences of the definition of core used by Arlo-Costa and Parikh is that a probability function is never coreless: full beliefs are always derivable from coherent conditional probability -- at least this can be shown for spaces containing all unit sets). Perhaps a similar argument can be also marshalled for two-place probability.

The second point is that the normative force of Huber's argument does not seem capable of convincing skeptics. After all, a philosopher following Kyburg's main ideas about acceptance is an agent who "knowingly has beliefs that are not both consistent and deductively closed." Such an agent can be perfectly aware of this fact but refuse to see it as a defect of his belief set. Indeed, an agent can regard it as a virtue. To be sure, Kyburg himself tends to see full logical closure as 'conjunctivitis': some sort of defective aspect of most theories of rationality. So an agent who adopts a high probability threshold view of belief will not at all view as odd the possibility of knowingly having beliefs that are not logically closed.

The second, more important, argument for ranking functions is a completeness result offered in (Hild and Spohn, 2008) and rehearsed in Spohn's article in this volume. Roughly speaking, the theorem asserts the following: Iterated contractions obey certain axioms if and only if differences between ranks behave such and such; if differences between ranks behave such and such, then there is a ranking function measured on the ratio scale, i.e., unique up to a multiplicative constant, which exactly represents these differences.

This is a remarkable and interesting theorem that does various things at once. On the one hand, it offers the most complete axiomatization of iterated contraction available today. On the other hand, the theorem guarantees that if one accepts this axiomatization, then one is bound to accept rankings of the sort that Spohn has proposed. In other words, rankings uniquely represent contraction behavior. The theorem depends therefore on the tenability of the axioms for iterated contraction, an interesting and relatively open topic at the moment. In any case, this is a very important result that puts ranking theory at the same level as other theories of belief change that have been completely characterized, such as the AGM theory.

The remaining articles in Part II focus on arguments justifying some of the main tenets of probabilism. Colin Howson focuses on two controversial issues: the status of countable additivity (CA) as a fundamental axiom of probability, and the status of conditioning as a diachronic constraint on rationality. De Finetti offered well-known arguments against CA, but his arguments have been recently challenged in various ways (among others by extending the Dutch Book argument to infinity). Howson pays special attention to the arguments offered in (Cox, 1961). His conclusion is that "my personal opinion, for what it is worth, is that de Finetti has made a very persuasive case, which is strongly reinforced by Cox's result, against CA."

Regarding conditioning as a diachronic constraint on rationality, we have two opposed views in this volume: Skyrms who supports the arguments for conditioning as a dynamic rule, and Howson who presents the opposite view (but see also (Skyrms, 1993), which contains a more nuanced position than the one endorsed in this volume). Howson's argument is as follows. Suppose that Q represents your belief state tomorrow. Suppose also that P(A) = 1, and P(Q(A) = r) >0, where r < 1. Then it is easy to see that P(A|Q(A) = r) = 1. Suppose, finally, that tomorrow you learn that Q(A) = r by introspection. Hence Q(A) ≠ P(A|Q(A) = r) = 1 and you violate conditionalization. The new twist in this story is that the violation is actually required if you are to be consistent: "It follows that, far from being a condition of consistency, 'dynamic coherence' will actually lead to inconsistency" (p. 116).

Jim Joyce presents in this volume an important essay offering a "non-pragmatic vindication of probabilism." We need some definitions to introduce the main idea of Joyce's argument.

A credence function b assigns degrees of belief to elements of the partition X = {X1, . . . , XN}. Given a credence function b and truth-value assignment v for X, an epistemic scoring rule S produces a real number S(b, v) that measures the epistemic disutility of holding the credences b when v is actual. A credence function b is inadmissible relative to a scoring rule S when there is some alternative bS such that S(b, v) > S(bS, v) for all v. With these meager elements we can present the main result offered by Joyce.

If S satisfies two natural properties, and is finite on [0, 1] and continuous for all credence functions and all truth-value assignments, then:

i. Every incoherent credence function is inadmissible relative to S and, moreover, is strictly dominated by some coherent credence function, and

ii. Every coherent credence function is admissible relative to S.

The two properties used in the proof are a property called TRUTH DIRECTEDNESS and another called COHERENT ADMISSIBILIITY. The latter property is a weakening of propriety, a condition usually imposed on scoring rules. There are two versions of coherent admissibility:

COHERENT ADMISSIBILITY (WEAK VERSION) No coherent credence function b is ever strictly dominated, i.e. if c ≠ b then S(c, v) ≤ S(b, v) for some v.

COHERENT ADMISSIBILITY (STRONG VERSION) No coherent credence function b is ever weakly dominated, i.e. if c ≠ b then S(c, v) < S(b, v) for some v.

As Joyce explains elsewhere (Joyce, 2009), the article that appears in this book states the weak version, but argues for the strong version and uses the strong version in the proof. So the strong version is the one needed in the proof. Joyce thinks that in any case this does not affect the thrust of the argument because he believes that the strong version is indeed true.

Teddy Seidenfeld pointed out in a recent talk given by Joyce at CMU that the strong form of Coherent Admissibility entails that coherent previsions are Bayes solutions. So, in view of that, it remains open whether every scoring rule that satisfies Coherent Admissibility must be proper. Joyce recently offered a counterexample establishing that Coherent Admissibility is indeed weaker than propriety.

Alan Hajek offers in this volume various arguments against Joyce's result. One of them is that Joyce's argument assumes that "any coherent credence function can be rationally held." But depending on the content of the elements of the partition X, some credence assignments might be irrational (for example, they might violate principles of Direct Inference from chances). Joyce's response (Joyce, 2009) is that it is not his purpose to argue that any coherent set of credences is rational tout court: "I only claim that they should not be excluded on grounds of inadmissibility" (p. 27).

The second objection Hajek advances is that the argument presumes that for any partition X with n cells and any non-negative {b1, . . . , bN} summing to one, ch(X1) = b1, . . . , ch(XN) = bN is a feasible chance assignment. But dependent on the content of the propositions in X, it might be that some chance assignments are ruled out for metaphysical reasons. The response in (Joyce, 2009) is that the only thing that is needed is that given a non-negative {b1, . . . , bN} with ∑n bn = 1 and any partition X, there is at least an evidential situation in which b(Xn) = bn are the right credences to hold. To achieve this Joyce assumes a principle of EXTENSIONALITY that says that for any (ordered) N-element partitions X and Y, SX(., v) = SY(., v) for every (ordered) truth-value assignment v. So we have that given any non-negative {b1, . . . , bN} with ∑n bn = 1, there is some partition X with n cells such that b1, . . . , bN are the right credences to invest in the elements of the partition. To achieve this, we just need an N-sided die loaded so that the chance of side 1 coming up is b1, the chance of side 2 is b2, etc.

The collection closes with two essays that consider qualitative and non-probabilistic approaches to belief. In many logical models of non-monotonic reasoning and belief change researchers have appealed to degrees of belief, or degrees of disbelief, or degrees of non-belief (degrees of expectation). Hans Rott's paper attempts to show that these various structures can be combined into a unified whole. This yields a hierarchy that spans from guesses and expectations to a priori beliefs. Somewhere between the agent's expectations and the a priori beliefs, her attitudes might be the ones of (plain) belief. Where to draw the line? According to Rott, if there is such a threshold for belief, the process of demarcating it is context-dependent. So, belief remains elusive. Of course, all the doxastic notions deployed in the unified model are consistent and logically closed, avoiding the classical problems of some of the versions of probabilism considered in the first part of the book.

David Makinson elaborates on how the notion of levels of belief appears in the usual constructions used in non-monotonic reasoning. For example, we might define A |~K x to hold when x is a classical consequence of K' ∪ A for all maximal A-consistent subsets K' of K. This definition can be liberalized by requiring that K' ∪ A entails x only for certain selected maximal A-consistent subsets K' of K. Moreover, these sets are selected by deploying a relation < that prioritizes among the subsets of K, treating some as preferred to others. Makinson offers a philosophical interpretation of this relation <: "it is natural to treat this relation < as representing our confidence in the subset K', in other words the level of our belief in the truth of its elements" (p. 346). Makinson shows how the standard literature in non-monotonic consequence and belief revision avoided a direct reference to probability to articulate this notion of level of belief presupposed in most of the existing accounts of non-monotonic consequence.

Despite important lacunae (e.g., recent work on conditional probability and imprecise probabilities), Degrees of Belief rightfully bears its title, offering a comprehensive overview of recent work on quantitative and qualitative models of grades of belief. A detailed introduction and several excellent surveys make the book nearly self-contained, and various original essays which offer new and interesting results make the book a showcase for recent work. Thus Degrees of Belief should be received both as an excellent introduction to degrees of belief for non-experts and a useful resource for philosophers and other scholars working in formal epistemology and related areas. We should expect that Degrees of Belief will find readership for some years to come.

References

Arlo-Costa, Horacio, Bayesian Epistemology and Epistemic Conditionals: On the Status of the Export-Import Laws, Journal of Philosophy, Vol. XCVIII, 11, 555-598, 2001.

Arlo-Costa, Horacio, Qualitative and Probabilistic Models of Full Belief, Proceedings of Logic Colloquium '98, Lecture Notes on Logic 13, S. Buss, P. Hajek, P. Pudlak (eds.), ASL, A. K. Peters, 1999.

Arlo-Costa, Horacio and Parikh, Rohit, Conditional Probability and Defeasible Inference, Journal of Philosophical Logic 34, 97-119, 2005.

Cox, R.T., The Algebra of Probable Inference (Baltimore, The John Hopkins Press, 1961).

De Finetti, Bruno, Theory of Probability, Volume I (New York: Wiley, 1990).

Hild, Matthias and Wolfgang Spohn, The Measurement of Ranks and the Laws of Iterated Contraction, Artificial Intelligence, 172, 1195-1218, 2008.

Huber, Franz, The Consistency Argument for Ranking Functions, Studia Logica, 86, 299-329, 2007.

Joyce, Jim, Scoring Rules and Coherence, Handout of a Talk, CMU, November 19, 2009.

Kaplan, Mark, Rational Acceptance, Philosophical Studies, 40, 129-145, 1981.

Levi, Isaac, and The Enterprise of Knowledge: An Essay on Knowledge, Credal. Probability and Chance (Cambridge, MIT Press, 1983).

Maher, Patrick, Betting on Theories (Cambridge, Cambridge UP, 1993).

Shackle, George L.S., Expectation in Economics (Cambridge, Cambridge UP, 1949).

Shackle, George L.S., Decision, Order and Time (2nd Edition, Cambridge, Cambridge UP, 1969).

Skyrms, Brian, A Mistake in Dynamic Coherence Arguments? Philosophy of Science, 60, 320-328, 1993.

Smets, Philippe, Showing How Measures of Quantified Belief are Belief Functions, in B. Bouchon, L. Foulloy and R.R. Yager (eds.), Intelligent Systems for Information Processing: From Representation to Applications (Amsterdam, Elsevier, 265-276, 2002).

Van Fraassen, Bas, Fine-Grained Opinion, Probability and the Logic of Full Belief, Journal of Philosophical Logic, 24, 349-377, 1995.

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