Artificial intelligence (AI) has become nearly ubiquitous in modern society, from components of mobile applications to medical support systems, and everything in between. In societally impactful systems imbued with AI, there has been increasing concern related to opaque AI, that is, artificial intelligence where it is unclear how or why certain decisions are reached. This has led to a recent boom in research on “explainable AI” (XAI), or approaches to making AI more explainable and understandable to human users. In the (...) military domain, numerous bodies have argued that autonomous and AI-enabled weapon systems ought not incorporate unexplainable AI, with the International Committee of the Red Cross and the United States Department of Defense both explicitly including explainability as a relevant factor in the development and use of such systems. In this article, I present a cautiously critical assessment of this view, arguing that explainability will be irrelevant for many current and near-future autonomous systems in the military (which do not incorporate any AI), that it will be trivially incorporated into most military systems which do possess AI (as these generally possess simpler AI systems), and that for those systems with genuinely opaque AI, explainability will prove to be of more limited value than one might imagine. In particular, I argue that explainability, while indeed a virtue in design, is a virtue aimed primarily at designers and troubleshooters of AI-enabled systems, but is far less relevant for users and handlers actually deploying these systems. I further argue that human–machine teaming is a far more important element of responsibly using AI for military purposes, adding that explainability may undermine efforts to improve human–machine teamings by creating a prima facie sense that the AI, due to its explainability, may be utilized with little (or less) potential for mistakes. I conclude by clarifying that the arguments are not against XAI in the military, but are instead intended as a caution against over-inflating the value of XAI in this domain, or ignoring the limitations and potential pitfalls of this approach. (shrink)

As Vetter says, we are at the “beginning of the debate, not the end” (2015: 300) when it comes to evaluating her potentiality-based account of metaphysical modality. This paper contributes to this developing debate by highlighting three problems for Vetter’s account. Specifically, I begin (§1) by articulating some relevant details of Vetter’s potentiality-based view. This leads to the first issue (§2), concerning unclarity in the idea of degrees of potentiality. Similarly, the second issue (§3) raises trouble for Vetter’s proposed individuation (...) conditions for potentialities. Finally, the third issue (§4) is about apparently unmanifestable intrinsic potentialities, and suggests that there might be some deeper problems with anchoring metaphysical possibilities in concrete objects. More generally, though the issues detailed here are problematic, I do not take them to be fatal. However, they do show that, at minimum, further clarification of Vetter’s potentiality view is required. As Vetter says, we are at the “beginning of the debate, not the end” (2015: 300) when it comes to evaluating her potentiality-based account of metaphysical modality. This paper contributes to this developing debate by highlighting three problems for Vetter’s account. Specifically, I begin (§1) by articulating some relevant details of Vetter’s potentiality-based view. This leads to the first issue (§2), concerning unclarity in the idea of degrees of potentiality. Similarly, the second issue (§3) raises trouble for Vetter’s proposed individuation conditions for potentialities. Finally, the third issue (§4) is about apparently unmanifestable intrinsic potentialities, and suggests that there might be some deeper problems with anchoring metaphysical possibilities in concrete objects. More generally, though the issues detailed here are problematic, I do not take them to be fatal. However, they do show that, at minimum, further clarification of Vetter’s potentiality view is required. (shrink)

In international law and the ethics of war, there are a variety of actions which are seen as particularly problematic and presumed to be always or inherently wrong, or in need of some overwhelmingly strong justification to override the presumption against them. One of these actions is assassination, in particular, assassination of heads of state. In this essay I argue that the presumption against assassination is incorrect. In particular, I argue that if in a given scenario war is justified, then (...) assassination of the enemy state's leader is also justified, and in fact ought to be pursued as a means short of war. I defend this position on both consequential and deontic grounds, arguing that assassination is both more discriminate than war and serves to harm only those most responsible for the situation which justifies war in the first place. I conclude by arguing that a norm of assassination, far from being a destabilizing force, as some have argued, would in fact serve to reinforce international norms of rights and respect for persons by making clear that tyrants and would-be oppressors cannot hide behind military forces or notions of sovereignty to protect themselves from judgment and retribution. (shrink)

In a recent article Duncan Purves, Ryan Jenkins, and B. J. Strawser argue that in order for a decision in war to be just, or indeed the decision to resort to war to be just, it must be the case that the decision is made for the right reasons. Furthermore, they argue that this requirement holds regardless of how much good is produced by said action. In this essay I argue that their argument is flawed, in that it mistakes what (...) makes an agent morally good for what makes an act morally good. I argue that the main thrust of Purves et al.’s argument in fact undermines the conclusion they wish to draw, and that the reasons for one’s action do not make an in principle difference to the morality of actions in war. I further argue that this position undermines the traditional ad bellum just war constraint of right intention, and that the morality of actions in war is, at core, only concerned with outcomes. I conclude by clarifying that one’s reasons for action do in fact matter when deciding to enter war or kill in war, but only because one’s reasons significantly impact the way in which one acts. The purpose of this paper is to clear the theoretical space by showing why intentions/reasons do not in principle matter when assessing the morality of war (or killing), but this should not be taken as an argument that we should ignore intentions/reasons altogether. (shrink)

The principle of proportionality demands that a war (or action in war) achieve more goods than bads. In the philosophical literature there has been a wealth of work examining precisely which goods and bads may count toward this evaluation. However, in all of these discussions there is no mention of one of the most certain bads of war, namely the psychological harm(s) likely to be suffered by the combatants who ultimately must fight and kill for the purposes of winning in (...) conflict. This paper argues that harms to one’s own soldiers must be included in proportionality judgments, and goes on to argue that one of the most significant harms one’s soldiers face are the psychological stresses and traumas associated with combat. The arguments draw on a growing wealth of psychological literature exploring the connections between combatancy and psychological trauma, and highlight, in particular, the uniquely negative impact which killing has on a combatant’s mental well-being. The paper concludes that these factors place an almost certain and rather weighty negative weight in any proportionality calculations concerning wars with ground combatants who must fight “up close and personal”, and that for more remote warfighters, there is also evidence to show that they may suffer deep psychological harm as a result of their combat roles as well. The argument, however, does not attempt to demonstrate that these factors render war impermissible. Rather, it merely shows that these harms, or bads, which can be quite significant, must be factored into our considerations of proportionality. The arguments themselves are rather uncontroversial, but they bring to light an element in the moral calculus which is sadly overlooked in most discussions of the ethics of war. (shrink)

Contemporary proponents of republican political theory often focus on the concept of freedom as non-domination, and how best to promote it within a state. However, there is little attention paid to what the republican conception of freedom demands in the international realm. In this essay I examine what is required for an agent to enjoy freedom as non-domination, and argue that this might only be achieved for individuals if one of two possibilities is pursued internationally: either (1) all nations are (...) made equally powerful, such that none may arbitrarily impose its will on another without penalty, or (2) all nations are joined under a global sovereign which guarantees that the weaker states are not subject to the whims of the stronger. I further argue that the first condition cannot suffice for achieving true non-domination, and as a result, republicanism must prescribe working toward the establishment of a global state. This paper provides an important contribution to the literature by addressing the international implications of the republican conception of freedom. (shrink)

Discussions of political obligation and political authority have long focused on the idea that the commands of genuine authorities constitute content-independent reasons. Despite its centrality in these debates, the notion of content-independence is unclear and controversial, with some claiming that it is incoherent, useless, or increasingly irrelevant. I clarify content-independence by focusing on how reasons can depend on features of their source or container. I then solve the long-standing puzzle of whether the fact that laws can constitute content-independent reasons is (...) consistent with the fact that some laws must fail to bind due to their egregiously unjust content. Finally I defend my understanding of content-independence against challenges and show why it retains a place of special importance for questions about the law and political obligation. Content-independence highlights that it is some feature of the law or law-making process in general that is supposed to generate moral obligations for citizens, not the merits of particular laws. (shrink)

Epistemic trespassers judge matters outside their field of expertise. Trespassing is ubiquitous in this age of interdisciplinary research and recognizing this will require us to be more intellectually modest.

This paper demonstrates the practical and philosophical strengths of adopting Luciano Floridi’s “general definition of information” (GDI) for use in the information sciences (IS). Many definitions of information have been proposed, but little work has been done to determine which definitions are most coherent or useful. Consequently, doubts have been cast on the necessity and possibility of finding a definition. In response to these doubts, the paper shows how items and events central to IS are adequately described by Floridi’s conception (...) of information, and demonstrates how it helps clarify the muddy theoretical framework resulting from the many previous definitions. To this end, it analyzes definitions, popular in IS, that conceive of information as energy, processes, knowledge, and physical objects. The paper finds that each of these definitions produces problematic or counterintuitive implications that the GDI suitably accounts for. It discusses the role of truth in IS, notes why the GDI is preferable to its truth-requiring variant, and ends with comments about the import of such a theory for IS research and practice. (shrink)

Autonomous weapons systems (AWS), sometimes referred to as “killer robots”, are receiving evermore attention, both in public discourse as well as by scholars and policymakers. Much of this interest is connected with emerging ethical and legal problems linked to increasing autonomy in weapons systems, but there is a general underappreciation for the ways in which existing law might impact on these new technologies. In this paper, we argue that as AWS become more sophisticated and increasingly more capable than flesh-and-blood soldiers, (...) it will increasingly be the case that such soldiers are “in the power” of those AWS which fight against them. This implies that such soldiers ought to be considered hors de combat, and not targeted. In arguing for this point, we draw out a broader conclusion regarding hors de combat status, namely that it must be viewed contextually, with close reference to the capabilities of combatants on both sides of any discreet engagement. Given this point, and the fact that AWS may come in many shapes and sizes, and can be made for many different missions, we argue that each particular AWS will likely need its own standard for when enemy soldiers are deemed hors de combat. We conclude by examining how these nuanced views of hors de combat status might impact on meaningful human control of AWS. (shrink)

"Argues that active involvement in politics can be deeply fulfilling to the individual, and that the construction of identity for all activists is both about morality and about what one wants for oneself.

In this short paper, we show that a popular view in information science, information-as-thing, fails to account for a common example of information that seems physical. We then demonstrate how the distinction between types and tokens, recently used to analyse Shannon information, can account for this same example by viewing information as abstract, and discuss existing definitions of information that are consistent with this approach. -/- Dans ce court article nous montrons qu'une vision populaire en sciences de l'information, l'information en (...) tant qu’une chose, échoue à rendre compte d'un exemple commun d'information qui semble physique. Nous démontrons ensuite comment la distinction type/token, utilisée récemment pour analyser l'information de Shannon, peut rendre compte de ce même exemple en considérant l'information comme abstraite, et nous discutons des définitions existantes de l’information qui sont compatibles avec cette approche. (shrink)

Changing our minds isn't easy. Even when we recognize our views are disputed by intelligent and informed people, we rarely doubt our rightness. Why is this so? How can we become more open-minded, putting ourselves in a better position to tolerate conflict, advance collective inquiry, and learn from differing perspectives in a complex world? -/- Nathan Ballantyne defends the indispensable role of epistemology in tackling these issues. For early modern philosophers, the point of reflecting on inquiry was to understand (...) how our beliefs are often distorted by prejudice and self-interest, and to improve the foundations of human knowledge. Ballantyne seeks to recover and modernize this classical tradition by vigorously defending an interdisciplinary approach to epistemology, blending philosophical theorizing with insights from the social and cognitive sciences. -/- Many of us need tools to help us think more circumspectly about our controversial views. Ballantyne develops a method for distinguishing between our reasonable and unreasonable opinions, in light of evidence about bias, information overload, and rival experts. This method guides us to greater intellectual openness--in the spirit of skeptics from Socrates to Montaigne to Bertrand Russell--making us more inclined to admit that sometimes we don't have the right answers. With vibrant prose and fascinating examples from science and history, Ballantyne shows how epistemology can help us know our limits. (shrink)

It has become easy to make a case for the relevance, richness, and importance of philosophical thinking for information research and practice. [Introduction to a special issue].

In this position paper for the 2019 CSCW workshop Good Systems: Ethical AI for CSCW I propose one tool and one idea for navigating the complex ethical problem space that results from the interaction of human and/or AI agents in shared, hopefully cooperative, computing environments.

In lieu of an abstract, here is a brief excerpt of the content:Religion, the Globalization of War, and Restorative JusticeNathan TierneyAs the pace of globalization increases, the world's religions find themselves in a perilous dilemma that they have yet to resolve in either practical or conceptual terms. On the one hand, the globalization of markets exerts a powerful pressure toward consumerist and materialist values, which undermine and undercut religious perspectives and sensibilities. On the other hand, the globalization of war heightens (...) the intensity of these religious perspectives and sensibilities, and distorts them in the direction of violence and religious extremism. This dilemma plays itself out in different ways in the developed and developing world, but, as the term "globalization" indicates, it is a problem for all of us. Governments, in developing countries especially, often find themselves forced to choose between one horn of the dilemma or the other, with often disastrous results as they take one or the other side in a "West versus the rest" scenario. In the long run, the only viable solution is one that addresses both horns of the dilemma at the same time, and this is possible only if, in turn, religions themselves become truly global. This will require a large-scale and focused cooperative effort in which the religions of the world actively and jointly engage with both problems, working with governments, NGOs, religious communities, and interfaith groups to harmonize religious life with economics and to promote a culture of peace and justice.Because "globalization" is a familiar term in relation to markets, I'll begin by clarifying what I mean by the globalization of war. There are two main aspects to this phenomenon. First, the term refers to a specific transformation in the nature, purposes, and conditions of warfare brought about by the forces of globalization. By globalization I mean the growing trend of the world's cultural, economic, and political forces to bypass national borders and operate on a world scale. This process creates new possibilities for both integration and conflict. When that conflict passes beyond the possibility of diplomatic negotiation, we have the conditions for globalized war. Globalized war is not necessarily world war. It can be relatively local in its sphere of combat; for example, the U.S. invasion of Afghanistan was a collective response to a worldwide threat of terrorism. What makes it a globalized war, as distinct from international war, is the global nature of the forces that produced it and [End Page 79] are affected by it. Globalized war in this sense has come only lately onto the scene, but its scale and impact is likely to grow in the coming century.The second aspect of the globalization of war is the tendency of conflict to mutate beyond the interests and concerns of nation-states and be taken up by broader civilizational units, even if they were not originally a response to global pressures. The most likely trajectory for this mutation has been well described by Samuel P. Huntington in his influential article "The Clash of Civilizations" (1993) and his book-length treatment of the same subject (1997). Huntington argues that the fault lines of conflict will not be primarily ideological or economic but cultural, where "cultural" is to be understood at its broadest level—the level of civilizations. He divides the world into seven or eight competing civilizations: Western, Sinic, Japanese, Hindu, Islamic, Orthodox, Latin American, and possibly African. Societies sharing cultural affinities will cooperate with one another, and the attempt by the West to universalize its dominant version of consumer capitalism and liberal democracy will be resisted in an increasingly determined way—eventually to the point of outright war: "the next world war, if there is one, will be a war between civilizations."1In Huntington's analysis, then, the globalization of war refers to a coming clash of civilizations. He believes that religion will play a central role in this clash as the focal point of civilizations: "Civilizations are differentiated from each other by history, language, culture tradition and, most important, religion."2 While Western civilization has experienced several decades of decline and decay, in both its cultural unity and its sense of identity, other civilizations have grown both in economic terms and... (shrink)

Two theses are central to recent work on the epistemology of disagreement: Conciliationism:?In a revealed peer disagreement over P, each thinker should give at least some weight to her peer's attitude. Uniqueness:?For any given proposition and total body of evidence, the evidence fully justifies exactly one level of confidence in the proposition. 1This paper is the product of full and equal collaboration between its authors. Does Conciliationism commit one to Uniqueness? Thomas Kelly 2010 has argued that it does. After some (...) scene-setting (?1), in ?2 we explain and criticize Kelly's argument, thereby defeating his larger argument that Conciliationism deserves no dialectical special treatment. But we argue further that Conciliationists are committed to a disjunction, one of whose disjuncts is Uniqueness, that amounts to an ?extremely strong and unobvious position? (??3?4). If we are correct, theorists should not treat Conciliationism as a default position in debates about the epistemic significance of disagreement. (shrink)

Two theses figure centrally in work on the epistemology of disagreement: Equal Weight (‘EW’) and Uniqueness (‘U’). According to EW, you should give precisely as much weight to the attitude of a disagreeing epistemic peer as you give to your own attitude. U has it that, for any given proposition and total body of evidence, some doxastic attitude is the one the evidence makes rational (justifies) toward that proposition. Although EW has received considerable discussion, the case for U has not (...) been critically evaluated. Endorsing U, we argue, commits one to the highly controversial thesis that whatever fixes your rational attitudes can do so only by fixing what evidence you have. This commitment imposes a relatively demanding requirement on justified belief in U, one that we argue is not satisfied by what is currently the strongest available case for U, due to Roger White [2005]. Our challenge to U makes more trouble for its proponents than do the worries about U expressed by Gideon Rosen [2001] and Thomas Kelly [2010]. Moreover, if Kelly [2010] is correct in thinking that EW “carries with it a commitment to” U—a claim which we accept for reasons similar to Kelly’s but is beyond this paper’s scope (but see Ballantyne and Coffman [forthcoming])—then our challenge to U bears importantly on EW: to the extent that our challenge to U succeeds, EW also suffers. (shrink)

A key question has been underexplored in the literature on conscientious objection: if a physician is required to perform ‘medical activities,’ what is a medical activity? This paper explores the question by employing a teleological evaluation of medicine and examining the analogy of military conscripts, commonly cited in the conscientious objection debate. It argues that physicians (and other healthcare professionals) can only be expected to perform and support medical acts – acts directed towards their patients’ health. That is, physicians cannot (...) be forced to provide or support services that are not medical in nature, even if such activities support other socially desirable pursuits. This does not necessarily mean that medical professionals cannot or should not provide non-medical services, but only that they are under no obligation to provide them. (shrink)

Wolterstorff defends the claim not only that ‘God speaks’ through the Bible but also that the reader gains ever new insights upon subsequent readings of it. I qualify this project with the philosophical hermeneutics he rejects—namely that of Gadamer and Ricoeur. Wolterstorff thinks what he calls ‘authorial discourse interpretation’ provides warrant for religious communities believing that ‘God speaks’ to them through a text. In developing this hermeneutic, he dismisses the viability of Gadamer and Ricoeur's approach because, Wolterstorff asserts, their form (...) of interpretation is merely an operation performed on an artifact. While a cursory study of Gadamer and Ricoeur might support such dismissal, particularly Ricoeur's emphasis on writing's obliteration of dialogue, a closer study guided by the hermeneutic priority of questioning complicates Wolterstorff's caricature. If writing obliterates dialogue, what happens to questions and responses? My thesis is that dialogue with another is preserved through the hermeneutical arc. I demonstrate this through specifying distinct logics of question and answer that occur in the reading process, and I delimit these logics by way of appeal to contemporary literacy pedagogy and its taxonomies of questions. A voice does speak with and listen to a reader in the event of reading, in this case a God who is not behind but before the text. Isolating this other who speaks and listens provides reinforcement for constructive theological work aligned with Gadamer and Ricoeur's hermeneutics, and answers for the experience of hearing ‘God speak’ differently through sacred texts. (shrink)

ABSTRACT: Most of what we believe comes to us from the word of others, but we do not always believe what we are told. We often reject thinkers' reports by attributing biases to them. We may call this debunking. In this essay, I consider how debunking might work and then examine whether, and how often, it can help to preserve rational belief in the face of disagreement.

What makes for a good education? What does one need to count as well-educated? Knowledge, to be sure. But knowledge is easily forgotten, and today's knowledge may be obsolete tomorrow. Skills, particularly in critical thinking, are crucial as well. But absent the right motivation, graduates may fail to put their skills to good use. In this book, Nathan King argues that intellectual virtues-traits like curiosity, intellectual humility, honesty, intellectual courage, and open-mindedness-are central to any education worthy of the name. (...) Further, such virtues are crucial to our functioning well in everyday life, in areas as diverse as personal relationships, responsible citizenship, civil discourse, and personal success. Our struggles in these areas often result from a failure to think virtuously. Drawing upon recent work in philosophy and psychology, King paints a portrait of virtuous intellectual character-and of the vices such a character opposes. Filled with examples and applications, this book introduces readers to the intellectual virtues: what they are, why they matter, and how we can grow in them. (shrink)

Raymond Aron and his Dialogues in an Age of Ideologies examines the thought and rhetoric of the most interesting thinker of the twentieth century of whom no one has heard. This book investigates Raymond Aron's conversations on politics during the Cold War with several of his more well-known interlocutors including Jean-Paul Sartre, Friedrich Hayek, and Charles de Gaulle. Through exploring these dialogues on the subjects of Marxism, freedom, and nationalism, we see the prudence of Aron's politics of understanding as well (...) as the emphasis he places on and virtue he demonstrates in public discourse. Through his dialogues, Aron shows us not only how to think politically but also how to engage in constructive public debate. He stands as a model for us to emulate in our own age of ideologies. (shrink)

The Counterfactual Comparative Account of Harm says that an event is overall harmful for someone if and only if it makes her worse off than she otherwise would have been. I defend this account from two common objections.

There are certain uses of and and or that cannot be explained by their normal meanings as truth-functional connectives, even with sophisticated pragmatic resources. These include examples such as The cops show up, and a fight will break out (‘If the cops show up, a fight will break out’), and I have no friends, or I would throw a party (‘I have no friends. If I did have friends, I would throw a party.’). We argue that these uses are indeed (...) distinct from the more ordinary uses of and and or, but that they are nonetheless related in a principled way. To explain them we give an analysis of what we call the dynamic effects of connectives, which arise in all their uses. The special uses at issue are then argued to be instances where the connectives exhibit their dynamic effects without their truth-conditional meaning. (shrink)

Wrestling with God makes your faith stronger.

I argue that reflection on philosophers who could have been working among us but aren’t can lead us to give up our philosophical beliefs.

I defend the widely-held view that morally worthy action need not be motivated by a desire to promote rightness as such. Some have recently come to reject this view, arguing that desires for rightness as such are necessary for avoiding a certain kind of luck thought incompatible with morally worthy action. I show that those who defend desires for rightness as such on the basis of this argument misunderstand the relationship between moral worth and the kind of luck that their (...) argument employs. Consequently, the argument provides no reason to doubt the popular view that a desire for rightness as such is no part of virtue. I conclude by suggesting that a family of worries about merely accidentally right action presuppose one side of the recent debate about objectivism and perspectivism about moral rightness. (shrink)

Recent work on the nature of luck widely endorses the thesis that an event is good or bad luck for an individual only if it is significant for that individual. In this paper, I explore this thesis, showing that it raises questions about interests, well-being, and the philosophical uses of luck. In Sect. 1, I examine several accounts of significance, due to Pritchard (2005), Coffman (2007), and Rescher (1995). Then in Sect. 2 I consider what some theorists want to ‘do’ (...) with luck, taking important examples from epistemology (explaining Gettier-style examples) and political philosophy (offering a rationale for the just distribution of resources in society), while suggesting implications for significance. Drawing together lessons from Sects. 1 and 2, I develop a new account of significance in Sect. 3 before concluding with reflections on the debate in Sect. 4. (shrink)

I argue that there is moral luck, i.e., that factors beyond our control can affect how laudable or culpable we are.

While a growing body of scholarship identifies urban agriculture’s broad suite of benefits and drivers, it remains unclear how motivations to engage in urban agriculture (UA) interrelate or how they differ across cities and types of organizations. In this paper, we draw on survey responses collected from more than 250 UA organizations and businesses from 84 cities across the United States and Canada. Synthesizing the results of our quantitative analysis of responses (including principal components analysis), qualitative analysis of textual data (...) excerpted from open-ended responses, and a review of existing literature, we describe six motivational frames that appear to guide organizations and businesses in their UA practice: Entrepreneurial, Sustainable Development, Educational, Eco-Centric, DIY Secessionist, and Radical. Identifying how practitioners stack functions and frame their work is a first step in helping to differentiate the diverse and often contradictory efforts transforming urban food environments. We demonstrate that a wide range of objectives drive UA and that political orientations and discourses differ by geography, organizational type and size, and funding regime. These six paradigms provide a basic framework for understanding UA that can guide more in-depth studies of the gap between intentions and outcomes, while helping link historically and geographically specific insights to wider social and political economic processes. (shrink)

Recently, Michael Huemer has defended the Principle of Phenomenal Conservatism: If it seems to S that p, then, in the absence of defeaters, S thereby has at least some degree of justification for believing that p. This principle has potentially far-reaching implications. Huemer uses it to argue against skepticism and to defend a version of ethical intuitionism. I employ a reductio to show that PC is false. If PC is true, beliefs can yield justification for believing their contents in cases (...) where, intuitively, they should not be able to do so. I argue that there are cases where a belief that p can behave like an appearance that p and thereby make it seem to one that p. (shrink)

Rather infamously, Kit Fine provided a series of counter‐examples which purport to show that attempts to understand essence in terms of metaphysical necessity are ‘fundamentally misguided’. Here, my aim is to put forward a new version of modalism that is, I argue, immune to Fine's counter‐examples. The core of this new modalist account is a sparseness restriction, such that an object's essential properties are those sparse properties it has in every world in which it exists. After first motivating this sparseness (...) restriction, I proceed to show how the resulting sparse modalism circumvents Fine's original counter‐examples. After dismissing a potential problem concerning the membership relation, I conclude that, as at least one form of modalism is viable, the project of understanding essence in terms of metaphysical necessity is not so fundamentally misguided after all. (shrink)

David Lewis and Peter van Inwagen have claimed that there are no “knockdown” arguments in philosophy. Their claim appears to be at odds with common philosophical practice: philosophers often write as though their conclusions are established or proven and that the considerations offered for these conclusions are decisive. In this paper, I examine some questions raised by Lewis’s and van Inwagen’s contention. What are knockdown arguments? Are there any in philosophy? If not, why not? These questions concern the nature of (...) the philosophical enterprise and our answers have implications for the limits on the attitudes of informed, rational thinkers. (shrink)