It is shown for an arbitrary topos that the Law of the Excluded Middle holds in its propositional logic iff it satisfies the limited choice principle that every epimorphism from 2 = 1 ⊕ 1 splits.

We are concerned with the following problem. Suppose Γ and Σ are closed permutation groups on infinite sets C and W and ρ: Γ → Σ is a non-split, continuous epimorphism with finite kernel. Describe the possibilities for ρ. Here, we consider the case where ρ arises from a finite cover π: C → W. We give reasonably general conditions on the permutation structure W;Σ which allow us to prove that these covers arise in two possible ways. The first (...) way, reminiscent of covers of topological spaces, is as a covering of some Σ-invariant digraph on W. The second construction is less easy to describe, but produces the most familiar of these types of covers: a vector space covering its projective space. (shrink)

Angell's logic of analytic containment AC has been shown to be characterized by a 9-valued matrix NC by Ferguson, and by a 16-valued matrix by Fine. We show that the former is the image of a surjective homomorphism from the latter, i.e., an epimorphic image. The epimorphism was found with the help of MUltlog, which also provides a tableau calculus for NC extended by quantifiers that generalize conjunction and disjunction.

We characterize the epimorphisms in homotopy type theory (HoTT) as the fiberwise acyclic maps and develop a type-theoretic treatment of acyclic maps and types in the context of synthetic homotopy theory as developed in univalent foundations. We present examples and applications in group theory, such as the acyclicity of the Higman group, through the identification of groups with 0-connected, pointed 1-types. Many of our results are formalized as part of the agda-unimath library.

It was shown recently that epimorphisms need not be surjective in a variety K of Heyting algebras, but only one counter-example was exhibited in the literature until now. Here, a continuum of such examples is identified, viz. the variety generated by the Rieger-Nishimura lattice, and all of its (locally finite) subvarieties that contain the original counter-example K . It is known that, whenever a variety of Heyting algebras has finite depth, then it has surjective epimorphisms. In contrast, we show that (...) for every integer $n \geq 2$ , the variety of all Heyting algebras of width at most n has a non-surjective epimorphism. Within the so-called Kuznetsov-Gerčiu variety (i.e., the variety generated by finite linear sums of one-generated Heyting algebras), we describe exactly the subvarieties that have surjective epimorphisms. This yields new positive examples, and an alternative proof of epimorphism surjectivity for all varieties of Gödel algebras. The results settle natural questions about Beth-style definability for a range of intermediate logics. (shrink)

The concept of elementary epimorphism is introduced. Inverse systems of such maps are considered, and a dual of the elementary chain lemma is found (Cor. 4.2). The same is done for pure epimorphisms (Cor. 4.3 and 4.4). Finally, this is applied to certain inverse limits of flat modules (Thm. 6.4) and certain inverse limits of absolutely pure modules (Cor. 6.3).

We characterize, in syntactic terms, the ranges of epimorphisms in an arbitrary class of similar first-order structures. This allows us to strengthen a result of Bacsich, as follows: in any prevariety having at most \ non-logical symbols and an axiomatization requiring at most \ variables, if the epimorphisms into structures with at most \ elements are surjective, then so are all of the epimorphisms. Using these facts, we formulate and prove manageable ‘bridge theorems’, matching the surjectivity of all epimorphisms in (...) the algebraic counterpart of a logic \ with suitable infinitary definability properties of \, while not making the standard but awkward assumption that \ comes furnished with a proper class of variables. (shrink)

Using techniques developed by Comer on sheaf-theoretic duality for cylindric algebras, we refine a result of Judit Madarász by showing that epimorphisms are not surjective even in the class of simple infinite dimensional cylindric algebras.

Keywords: Recursively Enumerable; Computably Enumerable; Friedberg Splitting; Congruence Relation; Ideal; Quotient; Lattice.

We investigate the pair-splitting number $\germ{s}_{pair}$ which is a variation of splitting number, pair-reaping number $\germ{r}_{pair}$ which is a variation of reaping number and cardinal invariants of ideals on ω. We also study cardinal invariants of F σ ideals and their upper bounds and lower bounds. As an application, we answer a question of S. Solecki by showing that the ideal of finitely chromatic graphs is not locally Katětov-minimal among ideals not satisfying Fatou's lemma.

Split brains that result in two simultaneous streams of consciousness cut off from each other are wrongly held to be grounds for doubting the existence of the divinely created soul. The mistake is based on two related errors: first, a failure to appreciate the soul's dependence upon neurological functioning; second, a fallacious belief that if the soul is simple, i.e. without parts, then there must be a unity to its thought, all of its thoughts being potentially accessible to reflection or (...) even unreflective causal interactions. But a soul theorist can allow neurological events to keep some conscious thoughts unavailable to others. (shrink)

Starting with Marx and Freud, scholars have attempted to identify the primary ethical challenge of capitalism. They have named injustice, inequality, repression, exploitative empires, and capitalism psychic hold over all of us, among other else. Nimi Wariboko instead argues that the core ethical problem of capitalism lies in the split nature of the modern economy, an economy divided against itself. Production is set against finance, consumption against saving, and the future against the present. As the rich enjoy their lifestyle, their (...) fellow citizens live in servitude. The economy mimics the structure of our human subjectivity as Saint Paul theorizes in Romans 7: the law constitutes the subject as split, traversed by negativity. The economy is split, shot through with a fundamental antagonism. This fundamental negativity at the core of the economy disturbs its stability and identity, generating its destructive drive. The Split Economy develops a robust theoretical framework at the intersection of continental philosophy, psychoanalytic theory, theology, and political economy to reveal a fundamental dynamic at the heart of capitalism. (shrink)

This is a contribution to the study of the Muchnik and Medvedev lattices of non-empty Π01 subsets of 2ω. In both these lattices, any non-minimum element can be split, i. e. it is the non-trivial join of two other elements. In fact, in the Medvedev case, ifP > MQ, then P can be split above Q. Both of these facts are then generalised to the embedding of arbitrary finite distributive lattices. A consequence of this is that both lattices have decidible (...) ∃-theories. (shrink)

Lachlan [9] proved that there exists a non-recursive recursively enumerable degree such that every non-recursive r. e. degree below it bounds a minimal pair. In this paper we first prove the dual of this fact. Second, we answer a question of Jockusch by showing that there exists a pair of incomplete r. e. degrees a0, a1 such that for every non-recursive r. e. degree w, there is a pair of incomparable r. e. degrees b0, b2 such that w = b0 (...) V b1 and bi for i = 0, 1. (shrink)

In this paper, I contend that there are at least two essential traits that commonly define being an I: self-identity and self-consciousness. I argue that they bear quite an odd relation to each other in the sense that self-consciousness seems to jeopardize self-identity. My main concern is to elucidate this issue within the range of the transcendental philosophies of Immanuel Kant and Edmund Husserl. In the first section, I shall briefly consider Kant’s own rendition of the problem of the Egosplitting. (...) My reading of the Kantian texts reveals that Kant himself was aware of this phenomenon but eventually deems it an unexplainable fact. The second part of the paper tackles the same problematic from the standpoint of Husserlian phenomenology. What Husserl’s extensive analyses on this topic bring to light is that the phenomenon of the Ego-splitting constitutes the bedrock not only of his thought but also of every philosophy that works within the framework of transcendental thinking. (shrink)

Reverse mathematics is a program in the foundations of mathematics founded by Friedman and developed extensively by Simpson and others. The aim of RM is to find the minimal axioms needed to prove a theorem of ordinary, that is, non-set-theoretic, mathematics. As suggested by the title, this paper deals with two RM-phenomena, namely, splittings and disjunctions. As to splittings, there are some examples in RM of theorems A, B, C such that A↔, that is, A can be split into two (...) independent parts B and C. As to disjunctions, there are examples in RM of theorems D, E, F such that D↔, that is, D can be written as the disjunction of two independent parts E and F. By contrast, we show in this paper that there is a plethora of splittings and disjunctions in Kohlenbach’s higher-order RM. (shrink)

A splitting of an r.e. set A is a pair A1, A2 of disjoint r.e. sets such that A1 A2 = A. Theorems about splittings have played an important role in recursion theory. One of the main reasons for this is that a splitting of A is a decomposition of A in both the lattice, , of recursively enumerable sets and in the uppersemilattice, R, of recursively enumerable degrees . Thus splitting theor ems have been used to (...) obtain results about the structure of , the structure of R, and the relationship between the two structures. Furthermore it is fair to say that questions about splittings have often generated important new technical developments in recursion theory. In this article we survey most of the results and techniques associated with splitting properties of r.e. sets in ordinary recursion theory. (shrink)

Is it time to take a break from feminism? In this pathbreaking book, Janet Halley reassesses the place of feminism in the law and politics of sexuality. She argues that sexuality involves deeply contested and clashing realities and interests, and that feminism helps us understand only some of them. To see crucial dimensions of sexuality that feminism does not reveal--the interests of gays and lesbians to be sure, but also those of men, and of constituencies and values beyond the realm (...) of sex and gender--we might need to take a break from feminism. Halley also invites feminism to abandon its uncritical relationship to its own power. Feminists are, in many areas of social and political life, partners in governance. To govern responsibly, even on behalf of women, Halley urges, feminists should try taking a break from their own presuppositions. Halley offers a genealogy of various feminisms and of gay, queer, and trans theories as they split from each other in the United States during the 1980s and 1990s. All these incommensurate theories, she argues, enrich thinking on the left not despite their break from each other but because of it. She concludes by examining legal cases to show how taking a break from feminism can change your very perceptions of what's at stake in a decision and liberate you to decide it anew. (shrink)

In this paper, we first define the vector product in Minkowski space $\mathbb{R}_{4}^{7}$, which is identified with the space of spatial split-octonions. Next, we derive the $G_{2}-$ frame formulae for a seven dimensional Minkowski curve by using the spatial split-octonions and the vector product. We show that Frenet–Serret formulas are satisfied for a spatial split octonionic curve. We obtain the congruence of two spatial split octonionic curves and give relationship between the $G_{2}-$ frame and Frenet–Serret frame. Furthermore, we present the (...) Frenet–Serret frame with split octonions in $\mathbb{R}_{4}^{8}$. Finally, we give illustrative examples with Matlab codes. (shrink)

A common presupposition in the concepts literature is that concepts constitute a sin- gular natural kind. If, on the contrary, concepts split into more than one kind, this literature needs to be recast in terms of other kinds of mental representation. We offer two new arguments that concepts, in fact, divide into different kinds: (a) concepts split because different kinds of mental representation, processed independently, must be posited to explain different sets of relevant phenomena; (b) concepts split because different kinds (...) of mental representation, processed independently, must be posited to explain responses to different kinds of category. Whether these arguments are sound remains an open empirical question, to be resolved by future empirical and theoretical work. (shrink)

In this paper, I contend that there are at least two essential traits that commonly define being an I: self-identity and self-consciousness. I argue that they bear quite an odd relation to each other in the sense that self-consciousness seems to jeopardize self-identity. My main concern is to elucidate this issue within the range of the transcendental philosophies of Immanuel Kant and Edmund Husserl. In the first section, I shall briefly consider Kant’s own rendition of the problem of the Ego- (...) class='Hi'>splitting. My reading of the Kantian texts reveals that Kant himself was aware of this phenomenon but eventually deems it an unexplainable fact. The second part of the paper tackles the same problematic from the standpoint of Husserlian phenomenology. What Husserl’s extensive analyses on this topic bring to light is that the phenomenon of the Ego-splitting constitutes the bedrock not only of his thought but also of every philosophy that works within the framework of transcendental thinking. (shrink)

A splitting A1A2 = A of an r.e. set A is called a Friedberg splitting if for any r.e. set W with W — A not r.e., W — Ai≠0 for I = 1,2. In an earlier paper, the authors investigated Friedberg splittings of maximal sets and showed that they formed an orbit with very interesting degree-theoretical properties. In the present paper we continue our investigations, this time analyzing Friedberg splittings and in particular their orbits and degrees for (...) various classes of r.e. sets. (shrink)

After the first callosotomy surgeries were performed, the general consensus among the medical community was that severing the corpus callosum had relatively little, if any, effect on an individual's behavior. Nearly twenty years later, researchers discovered that, under experimental conditions, the two hemispheres could simultaneously maintain very different interpretations of the same stimulus. These findings immediately called into question the unity of subjective experience, a fundamental characteristic of human consciousness. How could the split‐brain patient not experience any disruption in his (...) experience as a unified self when the two hemispheres are physically and functionally disconnected? In this chapter, we review the research that has led to a conceptualization of the split brain as two minds within one body and the implications of this research for the scientific study of consciousness. We argue that consciousness is a neural function that emerges from the integration of information across available functional modules. (shrink)

The traditional scope theory of intensionality (STI) (see Russell 1905; Montague 1973; Ladusaw 1977; Ogihara 1992, 1996; Stowell 1993) is simple, elegant, and, for the most part, empirically adequate. However, a few quite troubling counterexamples to this theory have lead researchers to propose alternatives, such as positing null situation pronouns (Percus 2000) or actuality operators (Kamp 1971; Cresswell 1990) in the syntax of natural language. These innovative theories do correct the undergeneration of the original scope theory, but at a cost: (...) the situation pronoun and operator theories overgenerate, as argued extensively by Percus (2000) and Keshet (2008). This paper presents new data that supports the STI over other analyses, such as structures where DPs lose their de re readings in positions where syntactic movement is blocked. These data point the way to a new theory of intensionality. This new theory, called split intensionality, is a modification of the STI which aims to solve the problems raised for the original scope theory without overgenerating. The proposal calls for an additional intensional abstraction operator that creates an expression denoting an intension from an expression denoting an extension. When a DP moves to a position above this operator, it is interpreted de re; otherwise it is de dicto. The crucial part of the new proposal is that a DP may move above this operator and yet remain, for instance, below an intentional verb or inside an if-clause. Therefore, a DP within an island for syntactic movement may be de re and yet not move out of the island when the intensional abstraction operator is also within the island. (shrink)

Elizabeth Schechter explores the implications of the experience of people who have had the pathway between the two hemispheres of their brain severed, and argues that there are in fact two minds, subjects of experience, and intentional agents inside each split-brain human being: right and left. But each split-brain subject is still one of us.

We investigate splitting number and reaping number for the structure (ω) ω of infinite partitions of ω. We prove that ${\mathfrak{r}_{d}\leq\mathsf{non}(\mathcal{M}),\mathsf{non}(\mathcal{N}),\mathfrak{d}}$ and ${\mathfrak{s}_{d}\geq\mathfrak{b}}$ . We also show the consistency results ${\mathfrak{r}_{d} > \mathfrak{b}, \mathfrak{s}_{d} < \mathfrak{d}, \mathfrak{s}_{d} < \mathfrak{r}, \mathfrak{r}_{d} < \mathsf{add}(\mathcal{M})}$ and ${\mathfrak{s}_{d} > \mathsf{cof}(\mathcal{M})}$ . To prove the consistency ${\mathfrak{r}_{d} < \mathsf{add}(\mathcal{M})}$ and ${\mathfrak{s}_{d} < \mathsf{cof}(\mathcal{M})}$ we introduce new cardinal invariants ${\mathfrak{r}_{pair}}$ and ${\mathfrak{s}_{pair}}$ . We also study the relation between ${\mathfrak{r}_{pair}, \mathfrak{s}_{pair}}$ and other cardinal invariants. We (...) show that ${\mathsf{cov}(\mathcal{M}),\mathsf{cov}(\mathcal{N})\leq\mathfrak{r}_{pair}\leq\mathfrak{s}_{d},\ma thfrak{r}}$ and ${\mathfrak{s}\leq\mathfrak{s}_{pair}\leq\mathsf{non}(\mathcal{M}),\mathsf{non}(\mathcal{N})}$. (shrink)

We propose a Condorcet-consistent voting method that we call Split Cycle. Split Cycle belongs to the small family of known voting methods satisfying the anti-vote-splitting criterion of independence of clones. In this family, only Split Cycle satisfies a new criterion we call immunity to spoilers, which concerns adding candidates to elections, as well as the known criteria of positive involvement and negative involvement, which concern adding voters to elections. Thus, in contrast to other clone-independent methods, Split Cycle mitigates both (...) “spoiler effects” and “strong no show paradoxes.”. (shrink)

Many have claimed that split-brain patients are actually two persons. I maintain that both the traditional separation argument and the more recent sophistication argument for the two persons interpretation are inadequate on conceptual grounds. An autonomy argument is inadequate on empirical grounds. Overall, theoretical and practical consequences weigh heavily in favor of adopting a one person interpretation.

Splitting livers allows two people (usually an adult and a child) to receive a liver transplant from one donated adult liver, but the risks to the adult recipient are greater than if they had received the equivalent whole liver. It has been suggested, therefore, that splitting livers harms adult recipients. Without liver splitting, however, there would be few livers available for children, and paediatric waiting time and waiting list mortality would significantly increase. In this paper, we argue (...) that although splitting livers makes adults worse off, this should be considered sub-optimal benefit rather than harm. We explore justifications for sub-optimally benefitting adults in this way and consider alternatives to the current approach. We argue that splitting livers masks the more fundamental problem of low paediatric donation rates and that increasing the number of paediatric donations would improve the situation for both adult and paediatric liver patients. (shrink)

By splitting idempotent morphisms in the total and base categories of fibrations we provide an explicit elementary description of the Cauchy completion of objects in the categories Fib) of fibrations with a fixed base category \ and Fib of fibrations with any base category. Two universal constructions are at issue, corresponding to two fibered reflections involving the fibration of fibrations \.

We investigate some notions of splitting families and estimate sizes of the corresponding cardinal coefficients. In particular we solve a problem of P. Simon.

It is a common assumption in contemporary cognitive neuroscience that discovering a putative realized kind to be dissociably realized (i.e., to be realized in each instance by two or more distinct realizers) mandates splitting that kind. Here I explore some limits on this inference using two deceptively similar examples: the dissociation of declarative and procedural memory and Ramachandran's argument that the self is an illusion.

Based on extensive questionnaire data, this paper focuses on parents’ views about children’s right to decide about participation in research. The data originates from 4000 families participating in a longitudinal prospective screening as 1997. Although current regulations and recommendations underline that children should have influence over their participation, many parents in this study disagree. Most (66%) were positive providing information to the child about relevant aspects of the study. However, responding parents were split about whether or not children should at (...) some point be allowed decisional authority when participating in research: 41.6% of the parents reported being against or unsure. Those who responded positively believed that children should be allowed to decide about blood-sampling procedures (70%), but to a less extent about participation (48.5%), analyses of samples (19.7%) and biological bank storage (15.4%). That as many as possible should remain in the study, and that children do not have the competence to understand the consequences for research was strongly stressed by respondents who do not think children should have a right to decide. When asked what interests they consider most important in paediatric research, child autonomy and decision-making was ranked lowest. We discuss the implications of these findings. (shrink)

Neither the George Washington University embryo splitting experiment nor the technique of embryo splitting itself has ethical flaws. The experiment harmed or wronged no one, and the investigators followed intramural review procedures for the experiment, although some might fault them for failing to seek extramural consultation or for not waiting until national guidelines for research on preembryos were developed. Ethical objections to such cloning on the basis of possible loss of individuality, possible lessening of individual worth, and concern (...) about potential harm to the resulting children are discussed and challenged, as are objections to the creation of embryos for the purpose of genetic diagnosis. Many of the ethical questions raised by the George Washington experiment are similar to those posed by existing reproductive technologies that allow the simultaneous production of several embryos. A multidisciplinary group should consider whether regulation of cloning is needed, and laws should be enacted to prohibit a commercial market for all frozen embryos. (shrink)

An old conjecture of modal logics states that every splitting of the major systems K4, S4, G and Grz has the finite model property. In this paper we will prove that all iterated splittings of G have fmp, whereas in the other cases we will give explicit counterexamples. We also introduce a proof technique which will give a positive answer for large classes of splitting frames. The proof works by establishing a rather strong property of these splitting (...) frames namely that they preserve the finite model property in the following sense. Whenever an extension Λ has fmp so does the splitting Λ/f of Λ by f. Although we will also see that this method has its limitations because there are frames lacking this property, it has several desirable side effects. For example, properties such as compactness, decidability and others can be shown to be preserved in a similar way and effective bounds for the size of models can be given. Moreover, all methods and proofs are constructive. (shrink)

Some philosophers have argued that so long as two neural events, within a subject, are both of the same type and both carry the same content, then these events may jointly constitute a single mental token, regardless of the sort of causal relation to each other that they bear. These philosophers have used this claim—which I call the “singularity-through-redundancy” position—in order to argue that a split-brain subject normally has a single stream of consciousness, disjunctively realized across the two hemispheres. This (...) paper argues, against this position, that the kind of causal relations multiple neural events bear to each other constrains the mental tokens with which functionalists who are realists can identify them. (shrink)

We investigate some aspects of bounding, splitting, and almost disjointness. In particular, we investigate the relationship between the bounding number, the closed almost disjointness number, the splitting number, and the existence of certain kinds of splitting families.

In this paper I argue that split-brain syndrome is best understood within an extended mind framework and, therefore, that its very existence provides support for an externalist account of conscious perception. I begin by outlining the experimental aberration model of split-brain syndrome and explain both: why this model provides the best account of split-brain syndrome; and, why it is commonly rejected. Then, I summarise Susan Hurley’s argument that split-brain subjects could unify their conscious perceptual field by using external factors to (...) stand-in for the missing corpus callosum. I next provide an argument that split-brain subjects do unify their perceptual fields via external factors. Finally, I explain why my account provides one with an experimental aberration model which avoids the problems typically levelled at such views, and highlight some empirical predictions made by the account. The nature of split-brain syndrome has long been considered mysterious by proponents of internalist accounts of consciousness. However, in this paper I argue that externalist theories can provide a straightforward explanation of the condition. I therefore conclude that the ability of externalist accounts to explain split-brain syndrome gives us strong reason to prefer them over internalist rivals. (shrink)

The goal of this paper is to propose a unified approach to the split scope readings of negative indefinites, comparative quantifiers, and numerals. There are two main observations that justify this approach. First, split scope shows the same kinds of restrictions across these different quantifiers. Second, split scope always involves low existential force. In our approach, following Sauerland, natural language determiner quantifiers are quantifiers over choice functions, of type <<,t>,t>. In split readings, the quantifier over choice functions scopes above other (...) operators (such as intensional verbs like must or can). Determiner quantifiers leave a choice-function trace when they move and this trace combines with the noun restriction, which is interpreted low. That split scope always involves low existential force is derived, without stipulation, from Kratzer’s idea that low existential force can be achieved via binding (into the noun restriction). (shrink)

All cells have electric potentials across their membranes, but is there really compelling evidence to think that such potentials are used as instructional cues in developmental biology? Numerous reports indicate that, in fact, steady, weak bioelectric fields are observed throughout biology and function during diverse biological processes, including development. Bioelectric fields, generated upon amputation, are also likely to play a key role during vertebrate regeneration by providing the instructive cues needed to direct migrating cells to form a wound epithelium, a (...) structure unique to regenerating animals. However, mechanistic insight is still sorely lacking in the field. What are the genes required for bioelectric‐dependent cell migration during regeneration? The power of genetics combined with the use of zebrafish offers the best opportunity for unbiased identification of the molecular players in bioelectricity. BioEssays 29:1133–1137, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

To assess the ability of the disconnected cerebral hemispheres to recognize images of the self, a split-brain patient was tested using morphed self-face images presented to one visual hemifield at a time while making “self/other” judgments. The performance of the right and left hemispheres of this patient as assessed by a signal detection method was not significantly different, though a measure of bias did reveal hemispheric differences. The right and left hemispheres of this patient independently and equally possessed the ability (...) to self-recognize, but only the right hemisphere could successfully recognize familiar others. This supports a modular concept of self-recognition and other-recognition, separately present in each cerebral hemisphere. (shrink)

In this paper we extend to various classes of subreducts of hoops some results about splitting algebras. In particular we prove that every finite chain in the purely implicational fragment of basic hoops is splitting and that every finite chain in the \ fragment of hoops is splitting. We also produce explicitly the splitting equations in most cases.

This article analyzes US drone operations through a historical and ethnographic analysis of the remote split paradigm used by the US Air Force. Remote split refers to the globally distributed command and control of drone operations and entails a network of human operators and analysts in the Middle East, Europe, and Southeast Asia as well as in the continental United States. Though often viewed as a teleological progression of “unmanned” warfare, this paper argues that historically specific technopolitical logics establish the (...) conditions of possibility for the work of war to be divisible into discreet and computationally mediated tasks that are viewed as effective in US military engagements. To do so, the article traces how new forms of authorized evidence and expertise have shaped developments in military operations and command and control priorities from the Cold War and the “electronic battlefield” of Vietnam through the Gulf War and the conflict in the Balkans to contemporary deployments of drone operations. The article concludes by suggesting that it is by paying attention to divisions of labor and human–machine configurations that we can begin to understand the everyday and often invisible structures that sustain perpetual war as a military strategy of the United States. (shrink)