Much of the discussion surrounding the ethics of abortion has centered around the notion of personhood. This is because many philosophers hold that the morality of abortion is contingent on whether the fetus is a person - though, of course, some famous philosophers have rejected this thesis (e.g. Judith Thomson and Don Marquis). In this article, I construct a novel argument for the immorality of abortion based on the notion of impairment. This argument does not assume that the fetus is (...) a person - indeed, I concede (for the sake of argument) that the fetus is not a person - and hence the morality of abortion is not contingent on whether the fetus is a person. I finish by answering a plethora of objections to my argument, concluding that none of them are successful. (shrink)

This article is a response to Stephen Law's article ‘The evil-god challenge’. In his article, Law argues that if belief in evil-god is unreasonable, then belief in good-god is unreasonable; that the antecedent is true; and hence so is the consequent. In this article, I show that Law's affirmation of the antecedent is predicated on the problem of good (i.e. the problem of whether an all-evil, all-powerful, and all-knowing God would allow there to be as much good in the world (...) as there is), and argue that the problem of good fails. Thus, the antecedent is unmotivated, which renders the consequent unmotivated. Law's challenge for good-god theists is to show that good-god theism is not rendered unreasonable by the problem of evil in the same way that evil-god theism is rendered unreasonable by the problem of good. Insofar as the problem of good does not render belief in evil-god unreasonable, Law's challenge has been answered: since it is not unreasonable to believe in evil-god (at least for the reasons that Law gives) it is not unreasonable to believe in good-god. Finally, I show that – my criticism aside – the evil-god challenge turns out to be more complicated and controversial than it initially appears, for it relies on the (previously unacknowledged) contentious assumption that sceptical theism is false. (shrink)

Joona Räsänen, in his article ‘Ectogenesis, abortion and a right to the death of the fetus’, has argued for the view that parents have a right to the death of the fetus. In this article, I will explicate the three arguments Räsänen defends, and show that two of them have false or unmotivated premises and hence fail, and that the support he offers for his third argument is inconsistent with other views he expresses in his article. Therefore, I conclude that (...) there is no right to the death of the fetus—or, if there is one, Räsänen has not shown it. (shrink)

Trent Dougherty has argued that commonsense epistemology and skeptical theism are incompatible. In this paper, I explicate Dougherty’s argument, and show that (at least) one popular form of skeptical theism is compatible with commonsense epistemology.

This paper is a response to Tyler Wunder’s ‘The modality of theism and probabilistic natural theology: a tension in Alvin Plantinga's philosophy’ (this journal). In his article, Wunder argues that if the proponent of the Evolutionary Argument Against Naturalism (EAAN) holds theism to be non-contingent and frames the argument in terms of objective probability, that the EAAN is either unsound or theism is necessarily false. I argue that a modest revision of the EAAN renders Wunder’s objection irrelevant, and that this (...) revision actually widens the scope of the argument. (shrink)

Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic must demonstrate that agents are operating with a bad method or are in an epistemically cursed world. Such demonstration involves a significant step beyond conceivability and commits the skeptic to potentially convergent inquiry.

In my article "Even if the fetus is not a person, abortion is immoral: The impairment argument" (this journal), I defended what I called “The impairment argument” which purports to show that abortion is immoral. Bruce Blackshaw (2019) has argued that my argument fails on three accounts. In this article, I respond to his criticisms.

Skeptical theism is a popular response to arguments from evil. Many hold that it undermines a key inference often used by such arguments. However, the case for skeptical theism is often kept at an intuitive level: no one has offered an explicit argument for the truth of skeptical theism. In this article, I aim to remedy this situation: I construct an explicit, rigorous argument for the truth of skeptical theism.

Perry Hendricks’ impairment argument for the immorality of abortion is based on two premises: first, impairing a fetus with fetal alcohol syndrome is immoral, and second, if impairing an organism to some degree is immoral, then ceteris paribus, impairing it to a higher degree is also immoral. He calls this the impairment principle. Since abortion impairs a fetus to a higher degree than FAS, it follows from these two premises that abortion is immoral. Critics have focussed on the ceteris paribus (...) clause of TIP, which requires that the relevant details surrounding each impairment be sufficiently similar. In this article, we show that the ceteris paribus clause is superfluous, and by replacing it with a more restrictive condition, the impairment argument is considerably strengthened. There are no data in this work. (shrink)

Critics of skeptical theism often claim that if it (skeptical theism) is true, then we are in the dark about whether (or for all we know) there is a morally justifying for God to radically deceive us. From here, it is argued that radical skepticism follows: if we are truly in the dark about whether there is a morally justifying reason for God to radically deceive us, then we cannot know anything. In this article, I show that skeptical theism does (...) not entail that we are in the dark about whether (or for all we know) there is a morally justifying reason for God to deceive us. And hence arguments against skeptical theism that make use of this assumption fail. (shrink)

The “Embryo Rescue Case” (ERC) refers to a thought experiment that is used to argue against the view that embryos have a right to life (i.e. are persons). I will argue that cognitive science undermines the intuition elicited by the ERC; I will show that whether or not embryos have a right to life, our mental tools will make it very difficult to believe that embryos have said right. This suggests that the intuition elicited by the ERC is not truth (...) indicative. The upshot of this is that we have an undercutting defeater for our intuition that embryos do not have a right to life. (shrink)

Arguments from evil purport to show that some fact about evil makes it (at least) probable that God does not exist. Skeptical theism is held to undermine many versions of the argument from evil: it is thought to undermine a crucial inference that such arguments often rely on. Skeptical objections to skeptical theism claim that it (skeptical theism) entails an excessive amount of skepticism, and therefore should be rejected. In this article, I show that skeptical objections to skeptical theism have (...) a very limited scope: only those who reject certain (apparently) popular epistemological theories will be threatened by them. (shrink)

Perry Hendricks’ original impairment argument for the immorality of abortion is based on the impairment principle (TIP): if impairing an organism to some degree is immoral, then ceteris paribus, impairing it to a higher degree is also immoral. Since abortion impairs a fetus to a higher degree than fetal alcohol syndrome (FAS) and giving a fetus FAS is immoral, it follows that abortion is immoral. Critics have argued that the ceteris paribus is not met for FAS and abortion, and so (...) we proposed the Modified Impairment Principle (MIP) to avoid these difficulties. Dustin Crummett has responded, arguing that MIP is open to various counterexamples which show it to be false. He also shows that MIP can generate moral dilemmas. Here, we propose a modification to MIP that resolves the issues Crummett raises. Additionally, Alex Gillham has criticized our appropriation of Don Marquis’ ‘future like ours’ reasoning about the wrongness of impairment. We show that his objections have minimal implications for our argument. (shrink)

In cases in which we must choose between either (i) preventing a woman from remaining unwillingly pregnant or (ii) preventing a fetus from being killed, we should prevent the fetus from being killed. But this suggests that in typical cases abortion is wrong: typical abortions involve preventing a woman from remaining unwillingly pregnant over preventing a fetus from being killed. And so abortion is typically wrong—and this holds whether or not fetuses are persons.

At several points throughout his career, Foucault suggests that publishing texts without authors’ names attached would be a useful step towards dismantling what he calls the “author-function:” a social and political role structured according to the way discourse is treated and disseminated in a particular social setting. I discuss Foucault’s criticisms of the author-function in terms of its relationship to the political role of intellectuals, and I argue that the demise of this role cannot be achieved through the means of (...) authorial anonymity, as Foucault suggests. Rather, it must be undermined from a position within this role itself. (shrink)

It is often assumed that if the fetus is a person, then abortion should be illegal. Thomson1 laid the groundwork to challenge this assumption, and Boonin2 has recently argued that it is false: he argues that abortion should be legal even if the fetus is a person. In this article, I explain both Thomson’s and Boonin’s reason for thinking that abortion should be legal even if the fetus is a person. After this, I show that Thomson’s and Boonin’s argument for (...) legalised abortion fail; they have not given us good reason for thinking abortion should be legal.1 Finally, I argue that—if we play Boonin’s game—abortion should be illegal. When discussing the ethics and politics of abortion, whether the fetus is a person is usually central.3 4.2 However, Thomson1 long ago challenged this view. She argued that abortion is permissible even if the fetus is a person. To do so, she asks us to consider a case in which you are non-consensually taken to a hospital and hooked up to a famous violinist. The violinist, if he is to survive, needs to filter his blood through your body. After 9 months, he will be fine and you can unplug yourself and go on your way. If you unplug yourself prior to this, however, he will die. Is it permissible to unplug yourself? Thomson thinks the answer is ‘yes’. And this, she thinks, shows that abortion is permissible even if the fetus is a person. While the majority of her article focuses on the ethics of abortion, it is clear that she also aims to show that abortion should be legal if the fetus is a person; she would no doubt reject the view that the state is right to coerce you into …. (shrink)

The purpose of this essay is to point out the diversity in post-Proppian plot analysis—and, more specifically, to argue that within it one can discern two fundamentally different conceptions of narrative structure. These are not merely different theoretical grids superimposed upon the same phenomena, but represent, in fact, two objectively different types of narrative structure. These two types will be referred to as dramatic structure and instrumental structure, and they may be succinctly characterized by the antonyms 'play' and 'work' respectively. (...) It will be argued that there is a basis in Propp for both conceptions of narrative structure and that Bremond and Greimas, in their efforts to 'generalize' Propp, have each only isolated one of two tendencies coexisting in his analytic approach. Our point of departure will be Propp's concept of the basic unit of plot structure, which he terms the function. This is a complex term. Two senses are distinguished, biological and mathematical-logical. (shrink)

The structure of narrative discourse is the focus of much current research, but the classicist Walter Burkert argues for a revitalization of the historical approach to myth. He pushes the origins of myth beyond ritual to action patterns man shares with animals. His approach is evaluated in the context of Propp's historical analysis, which complements his 'morphological' approach to Russian folktales; and to Levi-Strauss's synchronic analysis of myth, which sees an ahistoric connection between the myths of North and South America.

P-zombies are creatures that are physically (functionally, behaviourally) like you and I and yet lack phenomenal consciousness. If such creatures are possible, it’s (typically) taken to show property dualism is true: phenomenal consciousness isn’t reducible to – nor does it supervene on – physical states. If inverted qualia are possible, it’s possible that you and I have identical physical states and yet you see tomatoes as green and I see tomatoes as red. If this is the case, then (again) property (...) dualism is (typically) taken to be true. In this article, I???ll show that p-zombies and inverted qualia – if they are actually possible – prove more than previously thought: if one thinks p-zombies or inverted qualia are possible, then one should endorse one of the four following theses: (i) substance dualism, (ii) we have even more reason to reject p-zombies and inverted qualia since they entail an even more radical conclusion than previously thought (i.e. substance dualism), (iii) eliminativism about selves, or (iv) friends of p-zombies and inverted qualia have homework: they need to show a relevant, plausible disanalogy between arguments for p-zombies and inverted qualia as traditionally stated and my parallel arguments that entail substance dualism. My purpose here isn’t to defend any of these particular options. Instead, my purpose is to highlight that these are the four options available to take. (shrink)

Many teachers appreciate discussing teaching and learning with others, and participating in a community of others who are also excited about pedagogy. Many philosophy teachers find meetings such as the biannual AAPT workshop extremely valuable for this reason. But in between face-to-face meetings such as those, we can still participate in a community of teachers and learners, and even expand its borders quite widely, by engaging in activities under the general rubric of “open education.” Open education can mean many things, (...) from sharing one’s teaching materials openly with others, to using and revising those created by others, to asking students to create open educational materials, and more. In this article I discuss the benefits and possible drawbacks of such activities, and I argue that the former outweigh the latter. (shrink)

Lougheed argues that a possible solution to the problem of divine hiddenness is that God hides in order to increase the axiological value of the world. In a world where God exists, the goods associated with theism necessarily obtain. But Lougheed also claims that in such a world it’s possible to experience the goods of atheism, even if they don’t actually obtain. This is what makes a world with a hidden God more valuable than a world where God is unhidden, (...) and also more valuable than an atheistic world with no God. We show that Lougheed never considers the comparison between a world where God hides and an atheistic world. We argue that it’s possible for a person to experience theistic goods in a world where God does not exist, a possibility Lougheed never considers. If this is right it undermines his axiological solution to divine hiddenness. We conclude by showing how our discussion of the axiology of theism connects to the existential question of whether God exists; that is, we show that the axiological question is dependent on the existential question. (shrink)

This review-article deals with Duvall's book 'Faulkner's Marginal Couples' and evaluates his claim that his approach is 'primarily structuralist, with a special debt to the narrative semiotics of Greimas.' There is also a discussion of general issues in narrative semiotics not tied to any one researcher's approach.

I provide an updated version of The Impairment Argument against abortion and respond to numerous objections that can be (and have been) raised to it.

Skeptical theism is a popular response to arguments from evil. Recently, Matthew A. Benton, John Hawthorne, and Yoaav Isaacs have argued that the theses that ground skeptical theism are either false or limited in scope. In this article, I show that their objections rest on dubious assumptions about the nature of skeptical theism. Along the way, I develop and clarify the ambiguous parts of skeptical theism. The upshot of this is that—once the nature of skeptical theism is made clearer—it is (...) far more difficult to resist. (shrink)

We argue that the evil-god challenge is not an additional challenge for theists above and beyond the (much older) gap problem. One version of the evil-god challenge is merely a specific instance of the gap problem, and another is dependent on that specific instance of the gap problem. Therefore, the various solutions to the gap problem that theists have developed double as responses to the evil-god challenge, placing the evil-god challenge in a more vulnerable position than has been supposed.

Character education in schools has been high on the UK political agenda for the last few years. The government has invested millions in grants to support character education projects and declared its intention to make Britain a global leader in teaching character and resilience. But the policy has many critics: some question whether schools should be involved in the formation of character at all; others worry that the traits schools are being asked to cultivate are excessively competitive or military. In (...) this pamphlet Randall Curren sets out a robust defence of character education. He welcomes the political support it presently enjoys, but contends that greater clarity about the nature, benefits and acquisition of good character is essential. In particular, he argues that too narrow a focus on traits like perseverance and resilience is a serious mistake: these traits are only virtues when they are part of a wider set of moral and intellectual qualities, and when their exercise is guided by good judgment. Curren offers us a compelling and coherent account of what good character is and how it might be cultivated in schools. He explains why schools must be needs-supporting environments that provide students with opportunities to engage in rewarding activity, and why cultivating good character implies promoting the ‘fundamental British values’ of democracy, the rule of law, individual liberty, and mutual respect and tolerance. His groundbreaking pamphlet promises to expand the scope and strengthen the foundations of character education in British schools, and should go a long way towards allaying the fears of its detractors. (shrink)

Say theism is the view that an omnipotent, omniscient, perfectly loving, and perfectly good being exists. And say pointless atheism occurs just in case there’s an atheist who isn’t resistant to belief in God, and no greater good comes about on account of this atheist’s non-belief. In this article, I show that if two prominent views about evil and divine hiddenness are accepted, theism is compatible with pointless atheism—a result hitherto unnoticed. Furthermore, not only is theism compatible with pointless atheism, (...) it entails pointless atheism. This is significant because many objections to the argument from divine hiddenness have tried to show that all instances of non-resistant atheism are required for a greater good. But if I’m right, given theism, there need not be a point to non-resistant atheism. Indeed, we should expect there to be pointless atheism. (shrink)

At the centenary of Frank H. Knight’s Risk, Uncertainty, and Profit, we explore the continuing relevance of Knightian uncertainty to the theory and practice of entrepreneurship. There are three challenges facing such assessment. First, RUP is complex and difficult to interpret. The key but neglected element of RUP is that Knight’s account is not solely about risk and uncertainty as states of nature, but about how an agent’s beliefs about uncertain outcomes and confidence in those beliefs guide their choices. Second, (...) RUP is Knight’s only effort in this area. His subsequent career led elsewhere, so he did not engage with subsequent interpretations of this work. Third, much of the current literature emphasizes that decisions must be different under the two states of nature with a consequent misunderstanding of entrepreneurial agency. This paper addresses each challenge in sequence. First, we explicate Knight’s approach and explain why that approach is murky. Second, as a complement to Knight’s interpretation, we examine Frank P. Ramsey’s approach to subjective probabilities to help clarify Knight’s murky approach. What links Knight and Ramsey is a shared pragmatism about entrepreneurial agency under uncertainty that depends upon the beliefs about, and confidence in, their judgments of possible outcomes. This Knight-Ramsey approach does not require actor’s behaviors to be determined by the class of uncertain environment they face. We focus on the response by the entrepreneur to the existence of uncertainty in all its forms. We argue that this reductive account provides a foundation to examine common problems in management, including managerial hubris, the interaction between entrepreneurs and venture capitalists, and the need for experimentation in advance of new product and venture launches. Third, we critique current literature that favors epistemic purism about the ontology of risk and uncertainty and ignores Knight-Ramsey pragmatism in meeting uncertainty, such as using formal and informal institutions for uncertainty mitigation. Our account locates Frank Knight’s subtleties in entrepreneurial behavior firmly in the literature on entrepreneurial agency a century later. (shrink)

Shuford, Albert and Massengill proved, a half century ago, that the logarithmic scoring rule is the only proper measure of inaccuracy determined by a differentiable function of probability assigned the actual cell of a scored partition. In spite of this, the log rule has gained less traction in applied disciplines and among formal epistemologists that one might expect. In this paper we show that the differentiability criterion in the Shuford et. al. result is unnecessary and use the resulting simplified characterization (...) of the logarithmic rule to give novel arguments in favor of it. (shrink)

De facto objections to theism purport to show that theism is false, whereas de jure objections to theism claim that, whether or not theism is true, belief in God is irrational. Divine hiddenness – the fact that there are people who non-resistantly lack belief in God – is sometimes used as an argument against theism. In this article I will show that accepting the argument from divine hiddenness carries a high cost: it eliminates all de jure objections to theism. So (...) atheists can either have de jure objections to theism or the objection from divine hiddenness, but they cannot have both. (shrink)

The evil-god challenge is a challenge for theists to show that belief in God is more reasonable than belief in evil-god. In this article, I show that whether or not evil-god exists, belief in evil-god is unjustified. But this isn’t the case for belief in God: belief in God is probably justified if theism is true. And hence belief in God is (significantly) more reasonable than belief in evil-god, and the evil-god challenge has been answered.

Abortion restrictions are particularly good for black women—at least in the United States. This claim will likely strike many as outlandish. And numerous commentaries on abortion restrictions have suggested otherwise: many authors have lamented the effects of abortion restrictions on women, and black women in particular—these restrictions are bad for them, these authors say. However, abortion restrictions are clearly good for black women. This is because if someone is prevented from performing a morally wrong action, it’s good for her. For (...) example, it’s good for Sarah if she’s prevented from driving home drunk. However, since abortion is morally wrong, it follows that it’s good for women when they are prevented from getting an abortion. And since black women get abortions at disproportionately high rates, abortion restrictions are good in particular for black women. Indeed, this is an example of a positive effect of intersectionality. [lightly updated in light of it being rescinded.]. (shrink)

A discussion of Umberto Eco's notion of open and closed texts.

Our best social scientific theories try to tell us something about the social world. But is talk of a “social world” a metaphor that we ought not take too seriously? In particular, do the denizens of the social world—cultural values like the Protestant work ethic, firms like ExxonMobil, norms like standards of dress and behavior, institutions like the legal system, teams like FC Barcelona, conventions like marriages—exist? The question is not merely academic. Social scientists use these different social entities to (...) explain social phenomena such as the rise of capitalism, the decline in oil prices, or the effect of unions on the sports labor market. But how could these explanations possibly work if social entities don’t exist? (shrink)

All interpretations of the Portland Vase frieze to date have failed to see, much less explain, a crucial figural attribute in the frieze, one that proves to be both explicit and explicatory, and whose location and appearance secures the identification of not one but, indeed, three figures. Furthermore, the attribute lies at the heart of a distinct schema of figural grouping and arrangement which has also gone unheeded in previous treatments of the Portland Vase frieze. By dint of this previously (...) unknown attribute, one can straightforwardly read the opening scene of the frieze using the attributes therein provided, but the opening scene only. To complete the task, a second methodology–that which I laid out in Arion in 1992–is a categorical sine qua non. One can, as I have already shown, successfully navigate the entire frieze using the second methodology alone but, as so many others have shown, not contrariwise. These new findings–the attribute and figural plan–are clear proof that the artistic vision of the Portland Vase was purposefully executed in a two-part program. (shrink)

Brief, unfinished draft of a proposal for a novel and demanding, yet arguably well motivated, necessary condition for justified credence.

This article examines Richard Bauman's conception of oral narrative as performance and argues instead for a view of narrative texts as autonomous entities, analyzable in language-internal Saussurian terms. Plot is viewed as a matter of syntagmatic relations, and character as a matter of paradigmatic relations. A contrast is drawn between narrative truth (cohesion) and historical truth (correspondence). Alternatives to some of Bauman's analyses of narrative texts are proposed.

In this paper, I consider Sterba’s recent criticism of skeptical theism in context of his argument from evil. I show that Sterba’s criticism of skeptical theism shares an undesirable trait with all past criticisms of skeptical theism: it fails. This is largely due to his focus on causal connections and his neglect of logical connections. Because of this, his argument remains vulnerable to skeptical theism.

The pelvic exam is used to assess the health of female reproductive organs and so involves digital penetration by a physician. However, it is common practice for medical students to acquire experience in administering pelvic exams by performing them on unconscious patients without prior authorization. In this article, we argue that such unauthorized pelvic exams (UPEs) are sexual assault. Our argument is simple: in any other circumstance, unauthorized digital penetration amounts to sexual assault. Since there are no morally significant differences (...) between UPEs and other instances of digital penetration, UPEs are sexual assault. So, insofar as one is against sexual assault, one should be against UPEs. (shrink)

I’ve argued that those who endorse the argument from divine hiddenness must give up all pure de jure objections to theism, and this means that endorsing the argument is costly for atheists. Benjamin Curtis claims that this isn’t a significant cost for atheists. I show that—contrary to Curtis—there is a significant cost, and spell out why this is so. Furthermore, I show that my argument functions as a new argument for affirming reformed epistemology—the view that if theism is true, belief (...) in God is probably rational. (shrink)

A critical reading of Sarah Moss's "Probabilistic Knowledge".

Michael Huemer argues, on statistical grounds, that ``existence is evidence for immortality". On reasoning derived from the anthropic principle, however, mere existence cannot be evidence against any non-indexical, ``eternal'' hypothesis that predicts observers. This note attempts to advertise the much-flouted anthropic principle's virtues and workings in a new way, namely by calling attention to the fact that it is the primary intension of one's indexically-described evidence that best characterizes one's epistemic position.

The ethics of abortion considers whether abortion is immoral. Pro-choice philosophers think that it is not immoral, while pro-life philosophers think that it is. The axiology of abortion considers whether world would be better if the pro-choice or pro-life position is right. While much attention has been given to the ethics of abortion, there has been no attention given to the axiology of abortion. In this article, I seek to change that. I consider various arguments for thinking our world would (...) be better if the pro-choice position or the pro-life position is correct, ultimately concluding that it would be better if the pro-choice position is right. This is unfortunate, however, since there is no good reason to think the pro-choice position is correct. (shrink)

In several lectures, interviews and essays from the early 1980s, Michel Foucault startlingly argues that he is engaged in a kind of critical work that is similar to that of Immanuel Kant. Given Foucault's criticisms of Kantian and Enlightenment emphases on universal truths and values, his declaration that his work is Kantian seems paradoxical. I agree with some commentators who argue that this is a way for Foucault to publicly acknowledge to his critics that he is not, as some of (...) them charge, attempting a total critique of Enlightenment beliefs and values, but is instead attempting to transform them from within. I argue further that Foucault's self-professed Kantianism can also productively be read as a means of encouraging change in his intellectual audience, a call to courage to take up the thread of Enlightenment thought that Foucault finds in Kant's essay, `What is Enlightenment?': that of directing one's philosophical efforts towards questioning and transforming one's own present in its historical specificity, for the sake of promoting the values of freedom and autonomy therein. Though much of Kant's philosophical work is focused on that which lies outside of history, Foucault locates in some of it a concern for what is happening here and now that, I argue, he encourages his audience to take up for themselves through tracing his own intellectual lineage to Kant. In so doing, he encourages contemporary philosophers to consider the value and effects of their work on the present social and political contexts in which they live. (shrink)

The subject’s perspective objection (SPO) is an objection against externalist theories of justification, warrant, and knowledge. In this article, I show that externalists can accommodate the SPO while remaining externalist. So, even if the SPO is successful, it does not motivate internalism, and the primary motivation for internalism has been lost. After this, I provide an explanation for why so many people find cases that motivate the SPO convincing.

Paper presented at the Association for Informal Logic and Critical Thinking meeting in conjunction with the Central Division of the American Philosophical Association, Chicago, April 2004.