The pressure of oversight and scrutiny in the business-to-business purchasing process has the potential to cause psychological distress in purchasing professionals, giving rise to apprehensions about being ethically inappropriate. Utilizing depth interviews with public sector purchasing professionals in a phenomenological approach, the authors develop the notion of ethical purchasing dissonance to explain the psychological distress. An inductively derived conceptual framework is presented for ethical purchasing dissonance that explores its potential antecedents and consequences; illustrative propositions are presented, and managerial implications are (...) discussed. (shrink)

Elements of Mind provides a unique introduction to the main problems and debates in contemporary philosophy of mind. Author Tim Crane opposes those currently popular conceptions of the mind that divide mental phenomena into two very different kinds (the intentional and the qualitative) and proposes instead a challenging and unified theory of all the phenomena of mind. In light of this theory, Crane engages students with the central problems of the philosophy of mind--the mind-body problem, the problem of intentionality (or (...) mental representation), the problem of consciousness, and the problem of perception--and attempts to find solutions to these problems. A fresh and engaging exploration of the main issues in the philosophy of mind, Elements of Mind is easily accessible to students with no background in the subject. (shrink)

This article appeals to Thomas Aquinas in order to offer a construal of the nature of reason arguably preferable to that prominent in the Enlightenment. Thomas’s account neither espouses the notion that reason is devoid of any appetitive influence nor so conflates reason and will as to suggest that thinking becomes essentially a form of willing. His view does respect that the activity of willing is of fundamental import for the life of reason. Since the ultimate object of the will (...) is union with God, it follows that the virtue that specifically promotes the attainment of this end—the virtue of religion—has particular import because it aims at rectifying the will and is the most excellent among the moral virtues. In brief, this virtue promotes the optimal intellectual and moral flourishing of individuals as well as the realization of justice in society. (shrink)

This volume is a collection of 16 essays, old and new, relating history and exegesis in the writings of Bede and Adomnán, and in the lives of Thomas Becket. The first part consists of seven studies of Bede's writings, notably his biblical commentaries and his Ecclesiastical History. Two of the essays are published here for the first time. The five studies in the second part, devoted to Adomnán, discuss his life of Saint Columba (the Vita Columbae) and his guide to (...) the Holy Places (De locis sanctis). One essay ('The Bible as Map'), published posthumously, compares his presentation of a major theme, the earthly and heavenly Jerusalem, with the approach adopted by Bede. The third section consists of two essays on the lives of Thomas Becket that were composed shortly after his death. They examine, in the context of patristic exegesis, the biblical images invoked in the texts in order to show how the saint's biographers understood the complex relationship between hagiography and history. With the exception of the Jarrow Lecture on Bede and the essays on Becket, the studies in both parts were published originally in edited books, some of them now hard to come by. (shrink)

Some have claimed that people with very different beliefs literally see the world differently. Thus Thomas Kuhn: ‘what a man sees depends both upon what he looks at and also upon what his previous visual—conceptual experience has taught him to see’ (Kuhn 1970, p. ll3). This view — call it ‘Perceptual Relativism’ — entails that a scientist and a child may look at a cathode ray tube and, in a sense, the first will see it while the second won’t. The (...) claim is not, of course, that the child’s experience is ‘empty’; but that, unlike the scientist, it does not see the tube as a cathode ray tube. One way of supporting this claim is to say that one cannot see something as an F unless one has the concept F. Since the child plainly lacks the concept of a cathode ray tube, it cannot see it as a cathode ray tube. Although Perceptual Relativism is hard to believe, this supporting suggestion is not so implausible. After all, when we see (and more generally, perceive) the world, the world is presented to us in a particular way; so how can we see it as being that way unless we have some idea or conception of the way it is presented? We need not be committed to a representative theory of perception to think that perceptions in some sense represent the world. We can express this by saying that perceptions have content. Now it is a commonplace that the contents of beliefs and the other propositional attitudes involve concepts. The belief that this thing is a cathode ray tube involves, in some sense, the concept cathode ray tube. So the line of thought behind Perceptual Relativism may be expressed thus: seeing an F as an F is a state with content. (shrink)

This paper argues that a notion of statistical explanation, based on Salmon’s statistical relevance model, can help us better understand deep neural networks. It is proved that homogeneous partitions, the core notion of Salmon’s model, are equivalent to minimal sufficient statistics, an important notion from statistical inference. This establishes a link to deep neural networks via the so-called Information Bottleneck method, an information-theoretic framework, according to which deep neural networks implicitly solve an optimization problem that generalizes minimal sufficient statistics. The (...) resulting notion of statistical explanation is general, mathematical, and subcausal. (shrink)

This paper is a response to and discussion of Maddalena Bonelli’s “Women philosophers in antiquity: Open questions and some results.” It also aims to advance the general discussion of the issues Bonelli raises. In it I contextualise Bonelli’s discussion, and take up three of her questions: What is the status of the work of restoring ancient women to the philosophical canon? What criteria ought we to use to decide who counts as a philosopher? What sort of philosophy did women practice (...) in antiquity, and in what ways might the restoration of ancient women thinkers to the canon change the way we conceive of ancient philosophy itself? I consider the way in which Bonelli’s paper advances the discussion of each question, raise some worries about the discussions, and provide suggestions for how we might think about these issues further. I maintain that the reshaping of the philosophical canon that takes place when we integrate ancient women involves a reshaping of the discipline, and of our methods for accessing it. This is a result I argue we ought to embrace rather than resist. I conclude with a summary of the main contributions of Bonelli’s paper. (shrink)

In recent years there has been an increase in the number of calls for moral education to receive greater public attention. In our pluralist society, however, it is difficult to find agreement on what exactly moral education requires. Philosophical Discussion in Moral Education develops a detailed philosophical defence of the claim that teachers should engage students in ethical discussions to promote moral competence and strengthen moral character. Paying particular attention to the teacher's role, this book highlights the justification for, and (...) methods of, creating a classroom community of ethical inquiry. (shrink)

Tim Mulgan presents a penetrating examination of consequentialism: the theory that human behavior must be judged in terms of the goodness or badness of its consequences. The problem with consequentialism is that it seems unreasonably demanding, leaving us no room for our own aims and interests. In response, Mulgan offers his own, more practical version of consequentialism--one that will surely appeal to philosophers and laypersons alike.

In “Models and Reality” (1980), Putnam sketched a version of his internal realism as it might arise in the philosophy of mathematics. Here, I will develop that sketch. By combining Putnam’s model-theoretic arguments with Dummett’s reflections on Gödelian incompleteness, we arrive at (what I call) the Skolem-Gödel Antinomy. In brief: our mathematical concepts are perfectly precise; however, these perfectly precise mathematical concepts are manifested and acquired via a formal theory, which is understood in terms of a computable system of proof, (...) and hence is incomplete. Whilst this might initially seem strange, I show how internal categoricity results for arithmetic and set theory allow us to face up to this Antinomy. This also allows us to understand why “Models are not lost noumenal waifs looking for someone to name them,” but “constructions within our theory itself,” with “names from birth.”. (shrink)

Tim Button explores the relationship between words and world; between semantics and scepticism. -/- A certain kind of philosopher – the external realist – worries that appearances might be radically deceptive. For example, she allows that we might all be brains in vats, stimulated by an infernal machine. But anyone who entertains the possibility of radical deception must also entertain a further worry: that all of our thoughts are totally contentless. That worry is just incoherent. -/- We cannot, then, be (...) external realists, who worry about the possibility of radical deception. Equally, however, we cannot be internal realists, who reject all possibility of deception. We must position ourselves somewhere between internal realism and external realism, but we cannot hope to say exactly where. We must be realists, for what that is worth, and realists within limits. -/- In establishing these claims, The Limits of Realism critically explores and develops several themes from Hilary Putnam’s work: the model-theoretic arguments; the connection between truth and justification; the brain-in-vat argument; semantic externalism; and conceptual relativity. The book establishes the continued significance of these topics for all philosophers interested in mind, logic, language, or the possibility of metaphysics. (shrink)

Book reviewed in this article: Coping with Genetic Disorders. By John C. Fletcher. Genetics, Ethics and Parenthood. Edited by Karen Lebacqz. Screening and Counseling for Genetic Conditions: The Ethical, Social, and Legal Implications of Genetic Screening, Counseling, and Education Programs. A report of the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research.

The book argues that the category of mother is distinct from the category of woman and that many of the problems mothers face-socially, economically, politically, culturally, and psychologically-are specific to women's work and identity as mothers. Indeed, mothers, arguably more so than women in general, remain disempowered despite forty years of feminism. Mothers, thus, need a feminism of their own, one that positions mothers' concerns as the starting point for a theory and politic of empowerment. O'Reilly terms this new (...) mode of feminism matricentic feminism and the book explores how it is represented and experienced in theory, activism, and practice. The chapter on maternal theory examines the central theoretical concepts of maternal scholarship to include Adrienne Rich's distinction between mothering and motherhood, Sara Ruddick's model of maternal thinking and practice and Patricia Hill Collins' concept of othermothering while the chapter on activism considers the 21st century motherhood movement. Feminist mothering is likewise examined as the specific practice of matricentric feminism and this chapter discusses varies theories and strategies on and for maternal empowerment. Matricentric feminism is also examined in relation to the larger field of Feminist Theory and Women's Studies; here O'Reilly persuasively shows how matricentric feminism has been marginalized in feminist scholarship and considers the reasons for such exclusion and how such may be challenged and changed. (shrink)

Essential Philosophy of Psychiatry is a concise introduction to the growing field of philosophy of psychiatry. Divided into three main aspects of psychiatric clinical judgement, values, meanings and facts, it examines the key debates about mental health care, and the philosophical ideas and tools needed to assess those debates, in six chapters. In addition to outlining the state of play, Essential Philosophy of Psychiatry presents a coherent and unified approach across the different debates, characterized by a rejection of reductionism and (...) an emphasis on the ineliminability of uncodified skilled judgement. The first part, Values, outlines the debate about whether diagnosis of mental illness is essentially value-laden and argues that the prospects for reducing illness or disease to plainly factual matters are poor. It also explains the important role of skilled contextual judgement, rather than a principles-based deduction, in ethical judgement. The second part, Meanings, examines the central role of understanding and a shared first person perspective, both against attempts to reduce meaning to basic information-processing mechanisms and to explain away the difficulties of understanding psychopathology in recent models of delusion. The third part, Facts, shows the importance of uncodified clinical judgements, both in assessing the validity of psychiatric taxonomy and in the application of Evidence Based Medicine. Despite advances in the codifaction of practice and operationalism of diagnosis, an element of judgement remains in the assessment both of what, at one level, is good evidence for diagnosis and treatment and what, at a higher level, is good evidence for the validity of classification overall. (shrink)

Tim Bayne draws on philosophy, psychology, and neuroscience in defence of the claim that consciousness is unified. He develops an account of what it means to say that consciousness is unified, and then applies this account to a variety of cases - drawn from both normal and pathological forms of experience - in which the unity of consciousness is said to break down. He goes on to explore the implications of the unity of consciousness for theories of consciousness, for the (...) sense of embodiment, and for accounts of the self. The Unity of Consciousness draws on a wide range of findings within philosophy and the sciences of the mind to construct an account of the unity of consciousness that is both conceptually sophisticated and scientifically informed. (shrink)

I advocate scepticism about epistemic blame; the view that we have good reason to think there is no distinctively epistemic form of blame. Epistemologists often find it useful to draw a distinction between blameless and blameworthy norm violation. In recent years, this has led several writers to develop theories of ‘epistemic blame.’ I present two challenges against the very idea of epistemic blame. First, everything that is supposedly done by epistemic blame is done by epistemic evaluation, at least according to (...) a prominent view about the social role of epistemic evaluation. Parsimony considerations count against introducing an idle mechanism that does the same work as an existing one. Second, no current theory of epistemic blame includes a plausible account of the force of epistemic blame or the practices that could express it. I conclude that we should give up the notion of epistemic blame. (shrink)

One of the central problems in the study of consciousness concerns the ascription of consciousness. We want to know whether certain kinds of creatures—such as non-human animals, artificially created organisms, and even members of our own species who have suffered severe brain-damage—are conscious, and we want to know what kinds of conscious states these creatures might be in if indeed they are conscious. The identification of accurate markers of consciousness is essential if the science of consciousness is to have any (...) chance of success. (shrink)

Against transmission -- For attention -- Education in the minor key -- Anthropology, art and the university.

Does thought have distinctive experiential features? Is there, in addition to sensory phenomenology, a kind of cognitive phenomenology--phenomenology of a cognitive or conceptual character? Leading philosophers of mind debate whether conscious thought has cognitive phenomenology and whether it is part of conscious perception and conscious emotion.

Universals are putative objects like wisdom, morality, redness, etc. Although we believe in properties (which, we argue, are not a kind of object), we do not believe in universals. However, a number of ordinary, natural language constructions seem to commit us to their existence. In this paper, we provide a fictionalist theory of universals, which allows us to speak as if universals existed, whilst denying that any really do.

We outline a framework for analyzing episodes from the history of science in which the application of mathematics plays a constitutive role in the conceptual development of empirical sciences. Our starting point is the inferential conception of the application of mathematics, recently advanced by Bueno and Colyvan. We identify and discuss some systematic problems of this approach. We propose refinements of the inferential conception based on theoretical considerations and on the basis of a historical case study. We demonstrate the usefulness (...) of the refined, dynamical inferential conception using the well-researched example of the genesis of general relativity. Specifically, we look at the collaboration of the physicist Einstein and the mathematician Grossmann in the years 1912--1913, which resulted in the jointly published ``Outline of a Generalized Theory of Relativity and a Theory of Gravitation,'' a precursor theory of the final theory of general relativity. In this episode, an independently developed mathematical theory, the theory of differential invariants and the absolute differential calculus, was applied in the process of physical theorizing aiming at finding a relativistic theory of gravitation. We argue that the dynamical inferential conception not only provides a natural framework to describe and analyze this episode, but it also generates new questions and insights. We comment on the mathematical tradition on which Grossmann drew, and on his own contributions to mathematical theorizing. We argue that the dynamical inferential conception allows us to identify both the role of heuristics and of mathematical resources as well as the systematic role of problems and mistakes in the reconstruction of episodes of conceptual innovation and theory change. (shrink)

No-futurists ('growing block theorists') hold that that the past and the present are real, but that the future is not. The present moment is therefore privileged: it is the last moment of time. Craig Bourne (2002) and David Braddon-Mitchell (2004) have argued that this position is unmotivated, since the privilege of presentness comes apart from the indexicality of 'this moment'. I respond that no-futurists should treat 'x is real-as-of y' as a nonsymmetric relation. Then different moments are real-as-of different times. (...) This reunites privilege with indexicality, but entails that no-futurists must believe in ineliminably tensed facts. (shrink)

The phenomenal character of perceptual experience involves the representation of colour, shape and motion. Does it also involve the representation of high-level categories? Is the recognition of a tomato as a tomato contained within perceptual phenomenality? Proponents of a conservative view of the reach of phenomenal content say ’No’, whereas those who take a liberal view of perceptual phenomenality say ’Yes’. I clarify the debate between conservatives and liberals, and argue in favour of the liberal view that high-level content can (...) directly inform the phenomenal character of perception. (shrink)

This article surveys recent literature by Parsons, McGee, Shapiro and others on the significance of categoricity arguments in the philosophy of mathematics. After discussing whether categoricity arguments are sufficient to secure reference to mathematical structures up to isomorphism, we assess what exactly is achieved by recent ‘internal’ renditions of the famous categoricity arguments for arithmetic and set theory.

Keränen (2001) raises an argument against realistic (ante rem) structuralism: where a mathematical structure has a non-trivial automorphism, distinct indiscernible positions within the structure cannot be shown to be non-identical using only the properties and relations of that structure. Ladyman (2005) responds by allowing our identity criterion to include 'irreflexive two-place relations'. I note that this does not solve the problem for structures with indistinguishable positions, i.e. positions that have all the same properties as each other and exactly the same (...) relations to all objects (including themselves). I conclude that realistic structuralists must compromise and treat some structures eliminativistically. (shrink)

This volume of essays retrieves the largely unresearched thought and the original ideas of ancient women philosophers and carves out a space for them in the canon. The broad focus includes women thinkers in ancient Indian, Chinese, and Arabic philosophy as well as in the Greek and Roman philosophical traditions.

In 1997, a Scottish surgeon by the name of Robert Smith was approached by a man with an unusual request: he wanted his apparently healthy lower left leg amputated. Although details about the case are sketchy, the would-be amputee appears to have desired the amputation on the grounds that his left foot wasn’t part of him – it felt alien. After consultation with psychiatrists, Smith performed the amputation. Two and a half years later, the patient reported that his life had (...) been transformed for the better by the operation [1]. A second patient was also reported as having been satisfied with his amputation [2]. (shrink)

Brentano’s account of what he called intentionale Inexistenz — what we now call intentionality — is without question one of the most important parts of his philosophy, and one of the most influential ideas in late 19th-century philosophy. Here I will explain how this idea figures in Brentano’s central text, Psychology from an Empirical Standpoint (Brentano 1995a). I will then briefly explain how Brentano’s ideas about intentionality evolved after the first publication of this work in 1874, and how they were (...) then misinterpreted by some influential analytic philosophers. (shrink)

The present paper provides an analysis of Euler’s solutions to the Königsberg bridges problem. Euler proposes three different solutions to the problem, addressing their strengths and weaknesses along the way. I put the analysis of Euler’s paper to work in the philosophical discussion on mathematical explanations. I propose that the key ingredient to a good explanation is the degree to which it provides relevant information. Providing relevant information is based on knowledge of the structure in question, graphs in the present (...) case. I also propose computational complexity and logical strength as measures of relevant information. (shrink)

Michael Weisberg and Kenneth Reisman argue that the Volterra Principle can be derived from multiple predator-prey models and that, therefore, the Volterra Principle is a prime example for robustness analysis. In the current article, I give new results regarding the Volterra Principle, extending Weisberg’s and Reisman’s work, and I discuss the consequences of these results for robustness analysis. I argue that we do not end up with multiple, independent models but rather with one general model. I identify the kind of (...) situation in which this generalization approach may occur, and I analyze the generalized Volterra Principle from an explanatory perspective. (shrink)

In this ingenious and powerfully argued book Tim Maudlin sets out a novel account of logic and semantics which allows him to deal with certain notorious paradoxes which have bedevilled philosophical theories of truth. All philosophers interested in logic and language will find this a stimulating read.

The metaverse is equivocal. It is a science-fictional concept from the past; it is the present’s rough implementations; and it is the Promised Cyberland, expected to manifest some time in the future. The metaverse first emerged as a techno-capitalist network in a 1992 science fiction novel by Neal Stephenson. Our article thus marks the metaverse’s thirtieth anniversary. We revisit Stephenson’s original concept plus three sophisticated antecedents from 1972 to 1984: Jean Baudrillard’s simulation, Sherry Turkle’s networked identities, and Jacques Lacan’s schema (...) of suggestible consumers hooked up to a Matrix-like capitalist network. We gauge the relevance of these three antecedents following Meta’s recent promise to deliver a metaverse for the mainstream and the emergence of blockchain-oriented metaverse projects. We examine empirical data from 2021 and 2022, sourced from journalistic and social media (BuzzSumo, Google Trends, Reddit, and Twitter) as well as the United States Patent and Trademark Office. This latest chapter of the metaverse’s convoluted history reveals a focus not on virtual reality goggles but rather on techno-capitalist notions like digital wallets, crypto-assets, and targeted advertisements. The metaverse’s wallet-holders collect status symbols like limited-edition profile pictures, fashion items for avatars, tradable pets and companions, and real estate. Motivated by the metaverse’s sophisticated antecedents and our empirical findings, we propose a subtle conceptual re-orientation that respects the metaverse’s equivocal nature and rejects sanitised solutionism. Do not let the phantasmagorical goggles distract you too much: Big Meta is watching you, and it expects you to become a wallet-holder. Blockchain proponents want this as well. (shrink)

It is usual to distinguish between two kinds of doxastic attitude: standing or dispositional states, which govern our actions and persist throughout changes in consciousness; and conscious episodes of acknowledging the truth of a proposition. What is the relationship between these two kinds of attitude? Normally, the conscious episodes are in harmony with the underlying dispositions, but sometimes they come apart and we act in a way that is contrary to our explicit conscious judgements. Philosophers have often tried to explain (...) these situations in largely doxastic terms, by identifying one or other of the attitudes as our ‘real’ beliefs. This chapter argues that this is not generally realistic and we should appeal to a wider range of psychological attitudes. Such an account would be best supported by a picture of the unconscious mind which does not sharply separate the doxastic from the conative and the affective. (shrink)

The paper presents, and discusses, four candidate explanations of the structure, and construction, of the bees’ honeycomb. So far, philosophers have used one of these four explanations, based on the mathematical Honeycomb Conjecture, while the other three candidate explanations have been ignored. I use the four cases to resolve a dispute between Pincock and Baker about the Honeycomb Conjecture explanation. Finally, I find that the two explanations focusing on the construction mechanism are more promising than those focusing exclusively on the (...) resulting, optimal structure. The main reason for this is that optimal structures do not uniquely determine the relevant optimization leading to the optimal structure. (shrink)

Philosophy and model theory frequently meet one another. Philosophy and Model Theory aims to understand their interactions -/- Model theory is used in every ‘theoretical’ branch of analytic philosophy: in philosophy of mathematics, in philosophy of science, in philosophy of language, in philosophical logic, and in metaphysics. But these wide-ranging appeals to model theory have created a highly fragmented literature. On the one hand, many philosophically significant mathematical results are found only in mathematics textbooks: these are aimed squarely at mathematicians; (...) they typically presuppose that the reader has a significant background in mathematics; and little clue is given as to their philosophical significance. On the other hand, the philosophical applications of these results are then scattered across disconnected pockets of papers, separated by decades or more. -/- The first aim of Philosophy and Model Theory, then, is to consider the philosophical uses of model theory. On a technical level, we try to show how philosophically significant results connect to one another, and also to state the best version of a result for philosophical purposes. On a philosophical level, we show how similar dialectical situations arise repeatedly, across fragmented debates in varied philosophical areas. -/- The second aim of Philosophy and Model Theory, though, is to consider the philosophy of model theory. Model theory itself is rarely taken as the subject matter of philosophising (contrast this, say, with the philosophy of biology, or the philosophy of set theory). But model theory is a beautiful part of pure mathematics, and worthy of philosophical study in its own right. (shrink)

The phenomenology of agency has, until recently, been rather neglected, overlooked by both philosophers of action and philosophers of consciousness alike. Thankfully, all that has changed, and of late there has been an explosion of interest in what it is like to be an agent. 1 This burgeoning field crosses the traditional boundaries between disciplines: philosophers of psychopathology are speculating about the role that unusual experiences of agency might play in accounting for disorders of thought and action; cognitive scientists are (...) developing models of how the phenomenology of agency is generated; and philosophers of mind are drawing connections between the phenomenology of agency and the nature of introspection, phenomenal character, and agency itself. My aim in this paper is not to provide an exhaustive survey of this recent literature, but to provide a.. (shrink)

Amie Thomasson and Eli Hirsch have both attempted to deflate metaphysics, by combining Carnapian ideas with an appeal to ordinary language. My main aim in this paper is to critique such deflationary appeals to ordinary language. Focussing on Thomasson, I draw two very general conclusions. First: ordinary language is a wildly complicated phenomenon. Its implicit ontological commitments can only be tackled by invoking a context principle; but this will mean that ordinary language ontology is not a trivial enterprise. Second: ordinary (...) language often points in different directions simultaneously, so that a wide variety of existence questions cannot be deflated merely by appealing to ordinary language. (shrink)

Craig Callender [2022] provides a novel challenge to the non-arbitrariness principle. His challenge plays an important role in his argument for the rational permissibility of a non-exponential temporal discounting rate. But the challenge is also of wider interest: it raises significant questions about whether we ought to accept the non-arbitrariness principle as a constraint on rational preferences. In this paper, I present two reasons to resist Callender’s challenge. First, I present a reason to reject his claim that the non-arbitrariness principle (...) only targets pure time preferences. Second, I criticize the inference Callender draws from a modest claim to a much stronger claim. The modest claim is that it can be hard to reveal the contents of an agent’s preferences. The stronger claim is that this provides us with a reason to reject a certain kind of normative constraint on rational preferences. I argue that the modest claim doesn’t motivate the stronger claim. The upshot of my two arguments is good news for those sympathetic to the non-arbitrariness principle: Callender’s challenge can be overcome, at least as it currently stands. (shrink)

We defend the view that we are not identical to organisms against the objection that it implies that there are two subjects of every conscious state one experiences: oneself and one’s organism. We then criticize animalism —the view that each of us is identical to a human organism—by showing that it has unacceptable implications for a range of actual and hypothetical cases of conjoined twinning : dicephalus, craniopagus parasiticus, and cephalopagus.