Materialist metaphysicians want to side with physics, but not to take sides within physics.If we took literally the claim of a materialist that his position is simply belief in the claim that all is matter, as currently conceived, we would be faced with an insoluble mystery. For how would such a materialist know how to retrench when his favorite scientific hypotheses fail? How did the 18th century materialist know that gravity, or forces in general, were material? How did they know (...) in the 19th century that the electromagnetic field was material, and persisted in this conviction after the aether had been sent packing?The doctrine of physicalism casts a long shadow in contemporary philosophy, configuring all kinds of philosophical issues and projects. Unsurprisingly, its proponents argue that physicalism has all the obvious features necessary for a scientific hypothesis to be in what we will call ‘good standing,’ i.e. being worthy of serious scientific investigation. In fact, many claim much more, arguing that physicalism is a well-confirmed hypothesis and possibly amongst the best of our theories. But, as our second opening passage makes clear, a persistent worry has been that physicalism, or ‘materialism’ as van Fraassen terms it, is an edifice built on sand. For many philosophers question whether the ‘physical’ can be specified at all, or at least in a manner that will produce a physicalism that would be in good standing. (shrink)

Materialist metaphysicians want to side with physics, but not to take sides within physics.If we took literally the claim of a materialist that his position is simply belief in the claim that all is matter, as currently conceived, we would be faced with an insoluble mystery. For how would such a materialist know how to retrench when his favorite scientific hypotheses fail? How did the 18th century materialist know that gravity, or forces in general, were material? How did they know (...) in the 19th century that the electromagnetic field was material, and persisted in this conviction after the aether had been sent packing?The doctrine of physicalism casts a long shadow in contemporary philosophy, configuring all kinds of philosophical issues and projects. Unsurprisingly, its proponents argue that physicalism has all the obvious features necessary for a scientific hypothesis to be in what we will call ‘good standing,’ i.e. being worthy of serious scientific investigation. In fact, many claim much more, arguing that physicalism is a well-confirmed hypothesis and possibly amongst the best of our theories. But, as our second opening passage makes clear, a persistent worry has been that physicalism, or ‘materialism’ as van Fraassen terms it, is an edifice built on sand. For many philosophers question whether the ‘physical’ can be specified at all, or at least in a manner that will produce a physicalism that would be in good standing. (shrink)

My thesis is devoted to an attempt to offer, on behalf of mathematical Platonism, a reply to what may seem to be a powerful objection to it. The objection is this: If there is, as the Platonist supposes, mathematical knowledge of abstract objects, then there is a correlation between our beliefs and the mathematical facts. However, how is such a correlation to be explained given that mathematical objects are a-causal? The worry is that no explanation is possible and that this (...) is a considerable mark against mathematical Platonism. The source of the difficulty here is obvious: standard models for explaining such correlations proceed via the idea that facts cause beliefs, or that beliefs cause facts, or that there was a common cause. But these possibilities are not available to the Platonist given the a-causality of mathematical objects. ;I claim that such a correlation is explicable in a way which neither, contra expectation, renders abstract objects causal nor assigns to us capacities the exercise of which allows to us to explain the correlation on some implausible extension of a perceptual model. The thought is this: that explaining the correlation requires explaining conjunctions of facts and beliefs. But the conjunctions in question are, at least for the Platonism here considered, conjunctions of a brute fact and an explicable fact . However I argue, and this is the core of the thesis, that such conjunctions can always be explained by reiterating the brute fact and citing whatever explains the explicable fact. If this thesis about explanation is accepted, then such correlations are readily explicable. ;The rest of the thesis is devoted to examining various objections to this reply and to the thesis concerning explanation. I argue that they are not fatal. (shrink)

In his most recent collection of papers, J. Baird Callicott has continued to advance a communitarian environmental ethic inspired by the mid–century “land ethic” writings of Aldo Leopold. One subject of concern is a dilemma. Either: the position is open to a charge of “eco–fascism” because it holds that only one maximal community fundamentally matters and interests of smaller communities and individuals can be swamped by a fundamental concern with the whole. Or: it is a “paper tiger” because it says (...) that many communities fundamentally matter, but offers no advice about how we are settle prima–facie conflicts of obligations tied to our various communities. Callicott now offers two new second–order priority principles designed to steer the communitarian position through the dilemma. I outline the relevant parts of his new position. However, I argue that one of the principles ends up offering no coherent advice over the priority of the very communities that inspire interest in the position of Leopold. Callicott proposes that the more intimate and venerable of our communities should have priority, but these elements can come apart in the relevant cases. (shrink)

S.R.L. Clark is a prominent defender of environmental holism and an advocate of the better treatment of other species. Not coincidentally, he is also a defender of a Neoplatonic Theism which holds that the presuppositions of reason have theistic implications and the point of the world is to exemplify beauty, or all the forms of beauty. Here I examine certain aspects of his view. I do so because I’m drawn to his main holist conclusion: we should live according to those (...) rules that will allow as many creatures as possible, of as many kinds, their best chance of living a satisfactory life according to their kind. However, I express doubts about his general route to the principle. (shrink)

S.R.L. Clark is a prominent defender of environmental holism and an advocate of the better treatment of other species. Not coincidentally, he is also a defender of a Neoplatonic Theism which holds that the presuppositions of reason have theistic implications and the point of the world is to exemplify beauty, or all the forms of beauty. Here I examine certain aspects of his view. I do so because I’m drawn to his main holist conclusion: we should live according to those (...) rules that will allow as many creatures as possible, of as many kinds, their best chance of living a satisfactory life according to their kind. However, I express doubts about his general route to the principle. (shrink)

Books reviewed: Wayne Ouderkirk and Jim Hill, (eds), Land, Value, Community: Callicott and Environmental Philosophy John Meyer, Political Nature: Environmentalism and the Interpretation of Western Thought Val Plumwood, Environmental Culture: The Ecological Crisis of Reason David Schmidtz and Elizabeth Willott, (eds), Environmental Ethics: What Really Matters, What Really Works.

A major approach to the ethics of artificial intelligence is to use social choice, in which the AI is designed to act according to the aggregate views of society. This is found in the AI ethics of “coherent extrapolated volition” and “bottom–up ethics”. This paper shows that the normative basis of AI social choice ethics is weak due to the fact that there is no one single aggregate ethical view of society. Instead, the design of social choice AI faces three (...) sets of decisions: standing, concerning whose ethics views are included; measurement, concerning how their views are identified; and aggregation, concerning how individual views are combined to a single view that will guide AI behavior. These decisions must be made up front in the initial AI design—designers cannot “let the AI figure it out”. Each set of decisions poses difficult ethical dilemmas with major consequences for AI behavior, with some decision options yielding pathological or even catastrophic results. Furthermore, non-social choice ethics face similar issues, such as whether to count future generations or the AI itself. These issues can be more important than the question of whether or not to use social choice ethics. Attention should focus on these issues, not on social choice. (shrink)

Artificial intelligence experts are currently divided into “presentist” and “futurist” factions that call for attention to near-term and long-term AI, respectively. This paper argues that the presentist–futurist dispute is not the best focus of attention. Instead, the paper proposes a reconciliation between the two factions based on a mutual interest in AI. The paper further proposes realignment to two new factions: an “intellectualist” faction that seeks to develop AI for intellectual reasons and a “societalist faction” that seeks to develop AI (...) for the benefit of society. The paper argues in favor of societalism and offers three means of concurrently addressing societal impacts from near-term and long-term AI: advancing societalist social norms, thereby increasing the portion of AI researchers who seek to benefit society; technical research on how to make any AI more beneficial to society; and policy to improve the societal benefits of all AI. In practice, it will often be advantageous to emphasize near-term AI due to the greater interest in near-term AI among AI and policy communities alike. However, presentist and futurist societalists alike can benefit from each others’ advocacy for attention to the societal impacts of AI. The reconciliation between the presentist and futurist factions can improve both near-term and long-term societal impacts of AI. (shrink)

Epistemic modal operators give rise to something very like, but also very unlike, Moore's paradox. I set out the puzzling phenomena, explain why a standard relational semantics for these operators cannot handle them, and recommend an alternative semantics. A pragmatics appropriate to the semantics is developed and interactions between the semantics, the pragmatics, and the definition of consequence are investigated. The semantics is then extended to probability operators. Some problems and prospects for probabilistic representations of content and context are explored.

When I tell you that it’s raining, I describe a way the world is—viz., rainy. I say something whose truth turns on how things are with the weather in the world. Likewise when I tell you that the weatherman thinks that it’s raining. Here the truth of what I say turns on how things are with the weatherman’s state of mind in the world. Likewise when I tell you that I think that it’s raining. Here the truth of what I (...) say turns on how things are with my state of mind in the world. (shrink)

Despite its enduring insights, Durkheim’s theory of suicide fails to account for a significant set of cases because of its overreliance on structural forces to the detriment of other possible factors. In this paper, we develop a new theoretical framework for thinking about the role of culture in vulnerability to suicide. We argue that by focusing on the cultural dynamics of excessive regulation, particularly at the meso level, a more robust sociological model for suicide could be offered that supplements structure-heavy (...) Durkheimian theory. In essence, we argue that the relevance of cultural regulation to suicide rests on the (1) degree to which culture is coherent in sociocultural places, (2) existence of directives related to prescribing or proscribing suicide, (3) degree to which these directives translate into internalized meanings affecting social psychological processes, and (4) degree to which the social space is bounded. We then illustrate how our new theory provides useful insights into three cases of suicide largely neglected within sociology: specifically, suicide clusters in high schools, suicide in the military, and suicides of “despair” among middle-aged white men. We conclude with implications for future sociological research on suicide and suicide prevention. (shrink)

I develop a conception of expressivism according to which it is chiefly a pragmatic thesis about some fragment of discourse, one imposing certain constraints on semantics. The first half of the paper uses credal expressivism about the language of probability as a stalking-horse for this purpose. The second half turns to the question of how one might frame an analogous form of expressivism about the language of deontic modality. Here I offer a preliminary comparison of two expressivist lines. The first, (...) expectation expressivism, looks again to Bayesian modelling for inspiration: it glosses deontically modal language as characteristically serving to express decision-theoretic expectation (expected utility). The second, plan expressivism, develops the idea (due to Gibbard 2003) that this language serves to express 'plan-laden' states of belief. In the process of comparing the views, I show how to incorporate Gibbard's modelling ideas into a compositional semantics for attitudes and modals, filling a lacuna in the account. I close with the question whether and how plan expressivism might be developed with expectation-like structure. (shrink)

This paper defends a counterexample to Modus Tollens, and uses it to draw some conclusions about the logic and semantics of indicative conditionals and probability operators in natural language. Along the way we investigate some of the interactions of these expressions with 'knows', and we call into question the thesis that all knowledge ascriptions have truth-conditions.

This is a study in the meaning of natural language probability operators, sentential operators such as probably and likely. We ask what sort of formal structure is required to model the logic and semantics of these operators. Along the way we investigate their deep connections to indicative conditionals and epistemic modals, probe their scalar structure, observe their sensitivity to contex- tually salient contrasts, and explore some of their scopal idiosyncrasies.

We investigate a basic probabilistic dynamic semantics for a fragment containing conditionals, probability operators, modals, and attitude verbs, with the aim of shedding light on the prospects for adding probabilistic structure to models of the conversational common ground.

In this paper, we suggest that affect meets the traditional definition of “cognition” such that the affect–cognition distinction is phenomenological, rather than ontological. We review how the affect–cognition distinction is not respected in the human brain, and discuss the neural mechanisms by which affect influences sensory processing. As a result of this sensory modulation, affect performs several basic “cognitive” functions. Affect appears to be necessary for normal conscious experience, language fluency, and memory. Finally, we suggest that understanding the differences between (...) affect and cognition will require systematic study of how the phenomenological distinction characterising the two comes about, and why such a distinction is functional. (shrink)

A recent report by Persaud et al. [Persaud, N., McLeod, P. & Cowey, A. . Post-decision wagering objectively measures awareness. Nature Neuroscience 10, 257–261] addresses a fundamental issue in consciousness science: the experimental measurement of conscious content. The authors propose a novel technique, ‘post-decision wagering’, in which subjects place bets on the correctness of decisions or discriminations. In this note, I critique the authors’ claim that their method “measures awareness directly”.

By leveraging the case of Hindu sati, this paper elucidates the ways in which structure and culture condition suicidal behavior by way of social psychological and emotional dynamics. Conventionally, sati falls under Durkheim's discussion of altruistic suicides, or the self-sacrifice of underindividuated or excessively integrated peoples like widows in traditional societies. In light of the fact that Durkheim's interpretation was based on uneven data, nineteenth century Eurocentric beliefs, and a theoretical framework that can no longer resist modification and elaboration, by (...) reconsidering sati it is possible to sketch a new model that strengthens Durkheim's theory by making it more robust and generalizable. The following model is built on five principles. First, integration and regulation are not distinct causal forces, but overlapping contextual conditions. Second, to better explain the variation in suicidality across time and space, we must also pay attention to culture as it provides the underlying meanings of suicide that can increase the odds a person or class of persons become suicidal or are protected against suicidality. Third, structure still matters, but in many cases, the role power and power-differentials play must be considered. Fourth, understanding why and how people choose suicide depends on incorporating identity and status processes. Fifth, because the expression of social emotions like shame are patterned by structural and cultural conditions, to understand how suicidality is socioculturally patterned we must further explore the link between identity/status, social emotions, and structure and culture. (shrink)

Spoken word recognition involves a perceptual tradeoff between the reliance on the incoming acoustic signal and knowledge about likely sound categories and their co-occurrences as words. This study examined how adult second language (L2) learners navigate between acoustic-based and knowledge-based spoken word recognition when listening to highly variable, multi-talker truncated speech, and whether this perceptual tradeoff changes as L2 listeners gradually become more proficient in their L2 after multiple months of structured classroom learning. First language (L1) Mandarin Chinese listeners and (...) L1 English-L2 Mandarin adult listeners took part in a gating experiment. The L2 listeners were tested twice—once at the start of their intermediate/advanced L2 language class and again two months later. L1 listeners were only tested once. Participants were asked to identify syllable-tone words that varied in syllable token frequency (high/low according to a spoken word corpus) and syllable-conditioned tonal probability (most probable/least probable in speech given the syllable). The stimuli were recorded by 16 different talkers and presented at eight gates ranging from onset-only (gate 1) through onset+40 ms increments (gates 2 through 7) to the full word (gate 8). Mixed-effects regression modeling was used to compare performance to our previous study which used single-talker stimuli (Wiener, Lee, & Tao, 2019). The results indicated that multi-talker speech caused both L1 and L2 listeners to rely greater on knowledge-based processing of tone. L1 listeners were able to draw on distributional knowledge of syllable-tone probabilities in early gates and switch to predominantly acoustic-based processing when more of the signal was available. In contrast, L2 listeners, with their limited experience with talker range normalization, were less able to effectively transition from probability-based to acoustic-based processing. Moreover, for the L2 listeners, the reliance on such distributional information for spoken word recognition appeared to be conditioned by the nature of the acoustic signal. Single-talker speech did not result in the same pattern of probability-based tone processing, suggesting that knowledge-based processing of L2 speech may only occur under certain acoustic conditions, such as multi-talker speech. (shrink)

V. 1. Structures and processes -- v. 2. Domains and categories.

Cancer biology features the ascription of normal functions to parts of cancers. At least some ascriptions of function in cancer biology track local normality of parts within the global abnormality of the aberration to which those parts belong. That is, cancer biologists identify as functions activities that, in some sense, parts of cancers are supposed to perform, despite cancers themselves having no purpose. The present paper provides a theory to accommodate these normal function ascriptions—I call it the Modeling Account of (...) Normal Function (MA). MA comprises two claims. First, normal functions are activities whose performance by the function-bearing part contributes to the self-maintenance of the whole system and, thereby, results in the continued presence of that part. Second, MA holds that models of system-level activities that are (partly) constitutive of self-maintenance are improved by including a representation of the relevant function-bearing part and by making reference to the activity/activities that part performs which contribute(s) to those system-level activities. I contrast MA with two other accounts that seek to explicate the ascription of normal functions in biology, namely, the organizational account and the selected effects account. Both struggle to extend to cancer biology. However, I offer ecumenical readings which allow them to recover some ascriptions of normal function to parts of cancers. So, though I contend that MA excels in this respect, the purpose of this paper is served if it provides materials for bridging the gap between cancer biology, philosophy of cancer, and the literature on function. (shrink)

This paper discusses means for promoting artificial intelligence that is designed to be safe and beneficial for society. The promotion of beneficial AI is a social challenge because it seeks to motivate AI developers to choose beneficial AI designs. Currently, the AI field is focused mainly on building AIs that are more capable, with little regard to social impacts. Two types of measures are available for encouraging the AI field to shift more toward building beneficial AI. Extrinsic measures impose constraints (...) or incentives on AI researchers to induce them to pursue beneficial AI even if they do not want to. Intrinsic measures encourage AI researchers to want to pursue beneficial AI. Prior research focuses on extrinsic measures, but intrinsic measures are at least as important. Indeed, intrinsic factors can determine the success of extrinsic measures. Efforts to promote beneficial AI must consider intrinsic factors by studying the social psychology of AI research communities. (shrink)

The temporal structure for motivating, monitoring, and making sense of agency depends on encoding, maintaining, and accessing the right contents at the right times. These functions are facilitated by memory. Moreover, in informing action, memory is itself often active. That remembering is essential to and an expression of agency and is often active suggests that it is a type of action. Despite this, Galen Strawson (Proceedings of the Aristotelian Society, 103, 227–257, 2003) and Alfred Mele (2009) deny that remembering is (...) an action. They claim that memory fails to admit of control. Remembering is automatic—once remembering starts, the process can neither be stopped nor intervened on. Moreover, the agent does not initiate remembering. An agent has control over an event or process if and only if she has the capacity and opportunity to initiate and intervene on that event or process. Actions are events over which an agent has control. Since it is automatic, we fail to have control over remembering. Thus, remembering is not an action. In this paper, I draw out an assumption of Strawson’s and Mele’s accounts: an event-type whose tokens exhibit automaticity cannot, for that reason, be an action (§2). Against this assumption, I draw parallels between skilled bodily action and memory. I show that memory exhibits two defining features of skill: it can be learned with practice and it admits of attributions of excellence (§3). These features reveal how intelligent control is exerted in the exercise of skill despite apparent automaticity—control is gained over time (§4). Since exercises of skill are by definition actions and since memory exemplifies the defining features of skill, memory is a skill and instances of remembering are actions too. (shrink)

Focusing on cases which involve binding into epistemic modals with definite descriptions and quantifiers, I raise some new problems for standard approaches to all of these expressions. The difficulties are resolved in a semantic framework that is dynamic in character. I close with a new class of problems about de re readings within the scope of modals.

This paper critiques a number of standard ways of understanding the role of the metalanguage in a semantic theory for natural language, including the idea that disquotation plays a nontrivial role in any explanatory natural language semantics. It then proposes that the best way to understand the role of a semantic metalanguage involves recognizing that semantics is a model-based science. The metalanguage of semantics is language for articulating features of the theorist's model. Models are understood as mediating instruments---idealized structures used (...) to represent select aspects of the world, aspects the theorist is seeking some theoretical understanding of. The aspect of reality we are seeking some understanding of in semantics is a dimension of human linguistic competence---informally, knowledge of meaning. (shrink)

Desiring Whiteness provides a compelling new interpretation of how we understand race. Race is often seen to be a social construction. Nevertheless, we continue to deploy race thinking in our everyday life as a way of telling people apart visually. How do subjects become raced? Is it common sense to read bodies as racially marked? Employing Lacan's theories of the subject and sexual difference, Seshadri-Crooks explores how the discourse of race parallels that of sexual difference in making racial identity a (...) fundamental component of our thinking. Through close readings of literary and film texts, Seshardi-Crooks also investigates whether race is a system of difference equally determined by Whiteness. She argues that it is in relation to Whiteness that systems of racial classification are organized, endowing it with a power to shape human difference. (shrink)

Architectural design is typically limited by the constraints imposed by physical space. If and when opportunities to attenuate or extinguish these limits arise, should they be seized? Here it is argued that the limiting influence of spatial embedding should not be regarded as a frustrating tyranny to be escaped wherever possible, but as a welcome enabling constraint to be leveraged. Examples from the natural world are presented, and an appeal is made to some recent results on complex systems and measures (...) of interaction complexity. (shrink)

Cancer biologists ascribe normal functions to parts of cancer. Normal functions are activities that parts of systems are in some minimal sense supposed to perform. Cancer biologists’ finding normality within the abnormality of cancer pose difficulties for two main approaches to normal function. One approach claims that normal functions are activities that parts are selected for. However, some parts of cancers that have normal functions aren’t selected to perform them. The other approach claims that normal functions are part-activities typical for (...) the system and that contribute to survival/reproduction. However, cancers are too heterogeneous to establish what’s typical across a type. (shrink)

The view that actually has a reading on which it is a two-dimensional indexical modal operator has some problems.

ABSTRACT Sometimes, teams or players violate the rules of their leagues or associations. And sometimes, their leagues or associations respond by striking their wins from the official record. Especially in American college sports governed by the NCAA, this practice of vacating results is unpopular and widely decried. It should not be. Vacating wins can be an appropriate response to rules violations in higher-order competitions in the same way that it can be appropriate to call back a scoring play due to (...) a penalty. We outline the conceptual framework that makes sense of when, why, and how it is appropriate to vacate wins. (shrink)

The appendages of Drosophila develop from the imaginal discs. During the extensive growth of these discs cell lineages are for the most part unfixed, suggesting a strong role for cell‐cell interactions in controlling the final pattern of differentiation. However, during early and middle stages of development, discs are subdivided by strict lineage restrictions into a small number of spatially distinct compartments. These compartments appear to be maintained by stably inheriting states of gene expression; the compartmentspecific expression of two such ‘selector’ (...) ‐ like genes, engrailed and apterous, are critical for anterior‐posterior and dorso‐ventral compartmentalization, respectively. Recent work suggests that one purpose of compartmentalization is to establish regions of specialized cells near compartment boundaries via intercompartmental induction, using molecules like the hedgehog protein. Thus, compartments can act as organizing centers for patterning within compartments. Evidence for non‐compartmental patterning mechanisms will also be discussed. (shrink)

As Quine observed, the following sentence has a reading which, if true, would be of special interest to the authorities: Ralph believes that someone is a spy. This is the reading where the quantifier is naturally understood as taking wide scope relative to the attitude verb and as binding a variable within the scope of the attitude verb. This essay is interested in addressing the question what the semantic analysis of this kind of reading should look like from a Fregean (...) perspective—a perspective according to which attitude states are generally relations to structured Fregean thoughts composed of senses. The Fregean view faces a challenge of compositionality here. This essay describes the challenge and offers a response on the Fregean's behalf. (shrink)

Inspired by Weber’s charismatic carrier groups, Eisenstadt coined the term institutional entrepreneur to capture the rare but epochal collective capable of reorienting a group’s value-orientations and transferring charisma, while making them an evolutionary force of structural and cultural change. As a corrective to Parsons’ abstract, ‘top-down’ theory of change, Eisenstadt’s theory provided historical context and agency to moments in which societies experienced qualitative transformation. The concept has become central to new institutionalism, neo-functionalism, and evolutionary-institutionalism. Drawing from the former two, a (...) more robust theory of institutional entrepreneurship from an evolutionary-institutionalist’s perspective is posited. In essence, entrepreneurs formulate institutional projects with dual logic: a collective side focused on innovation where efforts are directed towards organizational symbolic mechanisms of integration and a self-interested side directed towards resource independence, monopolization, mobility, and power-dependence. While outcomes vary based on numerous environmental factors, success leads to greater structural/symbolic independence and ability to reconfigure physical-temporal-social-symbolic space. (shrink)

The National Science Foundation's Second Merit Criterion, or Broader Impacts Criterion , was introduced in 1997 as the result of an earlier Congressional movement to enhance the accountability and responsibility as well as the effectiveness of federally funded projects. We demonstrate that a robust understanding and appreciation of NSF BIC argues for a broader conception of research ethics in the sciences than is currently offered in Responsible Conduct of Research training. This essay advocates augmenting RCR education with training regarding broader (...) impacts. We demonstrate that enhancing research ethics training in this way provides a more comprehensive understanding of the ethics relevant to scientific research and prepares scientists to think not only in terms of responsibly conducted science, but also of the role of science in responding to identified social needs and in adhering to principles of social justice. As universities respond to the mandate from America COMPETES to “provide training and oversight in the responsible and ethical conduct of research”, we urge institutions to embrace a more adequate conception of research ethics, what we call the Ethical Dimensions of Scientific Research, that addresses the full range of ethical issues relevant to scientific inquiry, including ethical issues related to the broader impacts of scientific research and practice. (shrink)

It is generally agreed that using lethal or otherwise serious force in self-defense is justified only when three conditions are satisfied: first, there are some grounds for the defender to give priority to his own interests over those of the attacker (whether because the attacker has lost the protection of his right to life, for example, or because of the defender’s prerogative to prefer himself to others); second, the harm used is proportionate to the threat thereby averted; third, the harm (...) is necessary to avert that threat. The first and second conditions have been exhaustively discussed, but the third has been oddly neglected. Meanwhile a prominent school of thought has arisen, in the ethics of war, which seeks to ground the justification of killing in war in principles of individual self-defense. They too have failed to offer any substantive analysis of necessity, while at the same time appealing to it when it suits them to do so. In this paper, I attempt a detailed analysis of the necessity constraint on defensive force, and explore the implications of that analysis for the attempt to transpose principles of individual self-defense into the context of warfare. (shrink)