The Twin Cities is home to one of the largest and most vital GLBT populations in the nation-and one of the highest percentages of gay residents in the country. Drawn from the pioneering work of the Twin Cities GLBT Oral History Project-a collective organization of students, scholars, and activists devoted to documenting and interpreting the lives of GLBT people in Minneapolis and St. Paul-_Queer Twin Cities_ is a uniquely critical collection of essays on Minnesota's vibrant queer communities, past and present. (...) A rich blend of oral history, archival research, and ethnography, _Queer Twin Cities_ uses sexuality to chart connections between people's lives in Minnesota. Topics range from turn-of-the-century Minneapolis amid moral reform-including the highly publicized William Williams murder trial and efforts to police Bridge Square, aka "skid row"-to northern Minnesota and the importance of male companionship among lumber workers, and to postwar life, when the increased visibility of queer life went hand in hand with increased regulation, repression, and violence. Other essays present a portrait of early queer spaces in the Twin Cities, such as Kirmser's Bar, the Viking Room, and the Persian Palms, and the proliferation of establishments like the Dugout and the 19 Bar. Exploring the activism of GLBT/Two-Spirit indigenous people, the antipornography movements of the 1980s, and the role of gay men in the gentrification of Minneapolis neighborhoods, this volume brings the history of queer life and politics in the Twin Cities into fascinating focus. Engaging and revelatory, _Queer Twin Cities_ offers a critical analysis of local history and community and fills a glaring omission in the culture and history of Minnesota, looking not only to a remarkable past, but to our collective future. (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.

This chapter defends 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. It goes on to 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. In conclusion, the chapter finds that the too-many-subjects (...) problem to which animalism is vulnerable is far more intractable than the one that faces the rival psychological accounts. (shrink)

In 1993, investigators from George Washington University Medical Center separated the cells of 17 human embryos and produced 48 embryos, an average of three embryos for each original. The method, variously called twinning, cloning, embryo splitting, and blastomere separation, demonstrated that human embryos could be split to create genetically identical entities during conception. When publicized, however, the experiment brought to mind a different view of cloning repeated since the beginning of the new reproductive technologies. In the early 1970s, when (...) research on in vitro fertilization was in its infancy, commentators worried that cloning–defined as the duplication of persons–would be next, leading to a scenario of “boys genetically exactly like the father, girls like the mother, or individuals like some true or false hero of art, science, or sports, or like some demagogue or some saint.”. (shrink)

Animalism claims that we are animals, i.e. biological organisms of the primate species Homo sapiens. If there is a case in which the number of persons differs from the number of organisms, then animalism is false. Timothy Campbell and Jeff McMahan hold that there are, at least, two such cases: the dicephalus and the cephalopagus conjoined twinning cases. Recently, Eric Olson argued that either Campbell and McMahan's arguments assume the point at issue, rely on undefended assumptions, or constitute paradigmatic (...) anti-animalist claims. After characterising animalism, we address Campbell and McMahan's arguments and Olson's replies. We endorse Olson's first general objection and reject the second and third, nonetheless concluding that animalism isn't undermined by conjoined twinning cases. (shrink)

It has been argued that the possibility of monozygotic twinning disproves the conservative position on foetal personhood that defines the foetus as a person from conception. This article will canvass arguments for and against this proposition, in order to arrive at a conclusion as to the relative strength of this finding.

SummaryIn all European countries for which data exist, there was a maternal-age-specific decline in dizygotic twinning rates during the 1960s. For most of these countries, this decline continued through the 1970s, but in a few it apparently ceased. The causes of the declines and of their abatement are unknown. However, there were declines in sperm quality during the 1960s and 1970s in some parts of the world, including parts of Europe, and it is speculated here that this decline in (...) sperm quality may be related to the decline in dizygotic twinning. (shrink)

A brief account of Putnam's Twin Earth thought experiment and its significance, written for a general audience. Sadly, I can't include Helen De Cruz's drawing of it - check out the beautiful book!

In this paper we argue that, contrary to what is widely assumed in the literature, Kit Fine's fragmentalist interpretation of special relativity is not empirically equivalent to its orthodox reading. Our main argument crucially depends on a classic relativistic phenomenon, the Twin Paradox. We then discuss other variants of relativistic fragmentalism that promise to escape the argument.

We study the foundation of space-time theory in the framework of first-order logic (FOL). Since the foundation of mathematics has been successfully carried through (via set theory) in FOL, it is not entirely impossible to do the same for space-time theory (or relativity). First we recall a simple and streamlined FOL-axiomatization Specrel of special relativity from the literature. Specrel is complete with respect to questions about inertial motion. Then we ask ourselves whether we can prove the usual relativistic properties of (...) accelerated motion (e.g., clocks in acceleration) in Specrel. As it turns out, this is practically equivalent to asking whether Specrel is strong enough to “handle” (or treat) accelerated observers. We show that there is a mathematical principle called induction (IND) coming from real analysis which needs to be added to Specrel in order to handle situations involving relativistic acceleration. We present an extended version AccRel of Specrel which is strong enough to handle accelerated motion, in particular, accelerated observers. Among others, we show that~the Twin Paradox becomes provable in AccRel, but it is not provable without IND. (shrink)

The twin paradox (i.e. the reasoning made by the traveling twin, reversing the reasoning made by the earthbound twin, by which it is he who should be older) can be resolved by taking into account the relativity of simultaneity. However, simultaneity depends on a convention about the one-way velocity of light provided that the Reichenbach-Grünbaum hypothesis, is time. So far the resolution has been presented only for the Einstein convention. We show that for all possible choices of the relevant synchronization (...) parameters the calculations performed by both twins yield the same final results when carefully taking into account the relativity of simultaneity according to the conventions they have chosen. Since the final results do not depend on any of the synchronization parameters, the Reichenbach-Grünbaum hypothesis is thereby supported. (shrink)

Healthcare is one of the domains in which artificial intelligence (AI) is already having a major impact. Of interest is the idea of the digital twin (DT), an AI-powered technology that generates a real-time representation of the patient’s body, offering the possibility of more personalised care. Our main thesis in this paper is that the DT does not merely represent the patient’s body but produces a specific body. We argue, from a philosophical perspective and an ethical-phenomenological approach, that the virtual (...) body created by the DT has a major impact on one’s self-understanding, having consequences for gender expression and identification, and for health. This has deep implications for people who do not conform to gender normativity, for example, trans individuals. We advocate that, with thoughtful development, DT technology can and should be empowering, contributing to better addressing the diversity of bodies and facilitating trans people’s experience in healthcare contexts. (shrink)

In dicephalus conjoined twinning, it appears that two heads share a body; in cephalopagus, it appears that two bodies share a head. How many human animals are present in these cases? One answer is that there are two in both cases—conjoined twins are precisely that, conjoined twins. Another is that the number of humans corresponds to the number of bodies—so there is one in dicephalus and two in cephalopagus. I show that both of these answers are incorrect. Prominent accounts (...) of biological individuation, which treat the organism as an integrated whole, reveal that in these and other cases of conjoined twinning the ‘twins’ share a single human animal. This has a number of consequences for the debate about what we are. First, if animalism is true, individuals of our kind can be—and are—profoundly psychologically divided. Second, cephalopagus twinning does not divide animalism from its rivals, as has been claimed. Finally, animalists can reply to a vicious species of the ‘too many thinkers’ problem to which they are allegedly uniquely vulnerable. (shrink)

Horgan and Timmons, with their Moral Twin Earth arguments, argue that the new moral realism falls prey to either objectionable relativism or referential indeterminacy. The Moral Twin Earth thought experiment on which the arguments are based relies in crucial ways on the use of intuitions. First, it builds on Putnam’s well-known Twin Earth example and the conclusions drawn from that about the meaning of kind names. Further, it relies on the intuition that were Earthers and Twin Earthers to meet, they (...) would be able to have genuine moral disagreements. I will argue that the similarities with Putnam’s thought experiment are questionable and so the reliance on Putnam-like intuitions is questionable. I will then further argue that even if we accept the intuitions that Horgan and Timmons rely on, the anti-realist conclusion is not warranted due to there being more to the meaning of kind terms than the argument assumes. Once we develop the meaning of kind terms further we can acknowledge both that Earthers and Twin Earthers refer to different properties with their moral terms, and that in spite of that they can have a substantive disagreement due to a shared meaning component. (shrink)

Horgan and Timmons have argued that our intuitions about the semantics of non-moral language and moral language differ, and that while twin-earth semantic intuitions generate one result in Putnam´s twater case, moral twin-earth fails to generate comparable results for moral terms. Horgan and Timmon´s conclude from this that the semantic norms governing the use of natural kind terms differ from the semantic norms governing the use of moral terms. I will argue that Horgan and Timmons’ intuitive moral twin-earth argument fails (...) to derail the new moral realism. Further, I will discuss Boyd’s semantic theory and raise problems for it that do not rely on the use of moral twin-earth. (shrink)

Healthcare is one of the domains in which artificial intelligence (AI) is already having a major impact. Of interest is the idea of the digital twin (DT), an AI-powered technology that generates a real-time representation of the patient’s body, offering the possibility of more personalised care. Our main thesis in this paper is that the DT does not merely represent the patient’s body but produces a specific body. We argue, from a philosophical perspective and an ethical-phenomenological approach, that the virtual (...) body created by the DT has a major impact on one’s self-understanding, having consequences for gender expression and identification, and for health. This has deep implications for people who do not conform to gender normativity, for example, trans individuals. We advocate that, with thoughtful development, DT technology can and should be empowering, contributing to better addressing the diversity of bodies and facilitating trans people’s experience in healthcare contexts. (shrink)

This article examines how digitalization challenges the foundations of constitutionalism and, in particular, the notion of constitutional revolutions. It contends that Cyber-Physical Social Systems (CPSS), whose advent is already under way in industry, infrastructure, city management, mobility, and housing, have set a new logic in motion that relies on the replication of the social world through the so-called ‘digital twinning’. Drawing on societal constitutionalism and social theory, the article argues that this has significant consequences for how power is constitutionalized, (...) since the emerging ‘smart’ governance tends to permeate society and to dissolve the abstraction necessary for constitutional revolutions. While contemporary proposals from constitutional theory, such as digital constitutionalism and cybernetic socialism, address these transformations, they fall short of reviving the radical dimension of constitutional change. Finally, the article looks at how to re-specify the revolutionary legacy and how the notion of constituent power could play out vis-à-vis the digital sphere. (shrink)

This paper explores the twin transition in family businesses, examining the parallel development of digital technologies and sustainable business practices, both of which are part of the current European agenda for a more sustainable future. While not widely recognised for their investments in disruptive innovation and digitalisation, family businesses (FBs) are more inclined to perform incremental changes, often driven by a longstanding commitment to sustainability and collaboration with internal and external stakeholders. This contrast makes them an ideal subject for a (...) more in-depth exploration of these transformative trends. The aim of this study is to adopt a broader perspective in twin-transition analysis, incorporating social and economic performance alongside environmental sustainability in relation to digital transformation. Therefore, we establish a connection between the triple-bottom-line (TBL) approach and digital innovation in the unique reality of FBs. Our research approach is based on interviews conducted across multiple studies that explore FB dynamics and digitalisation in different industries and countries, supplemented by insights from secondary data. We analyse data through a directed qualitative content analysis. By adopting a broader perspective on sustainability—shifting from an exclusive focus on the environmental dimension to a TBL approach—our findings position FBs as key players in the twin transition, excelling at both addressing sustainability challenges and fostering digital innovation. These companies should prioritise aligning their strategies with equitable, viable and bearable principles in line with the TBL approach by fostering socio-emotional wealth, engaging younger generations in digital innovation and implementing work–life balance initiatives that enhance employee satisfaction and sustainability. Most of these strategies can also be replicated by non-family businesses, establishing FBs as exemplary leaders in the twin-transition journey. (shrink)

In dicephalus conjoined twinning, it appears that two heads share a body; in cephalopagus, it appears that two bodies share a head. How many human animals are present in these cases? One answer is that there are two in both cases—conjoined twins are precisely that, conjoined twins. Another is that the number of humans corresponds to the number of bodies—so there is one in dicephalus and two in cephalopagus. I show that both of these answers are incorrect. Prominent accounts (...) of biological individuation, which treat the organism as an integrated whole, reveal that in these and other cases of conjoined twinning the ‘twins’ share a single human animal. This has a number of consequences for the debate about what we are. First, if animalism is true, individuals of our kind can be—and are—profoundly psychologically divided. Second, cephalopagus twinning does not divide animalism from its rivals, as has been claimed. Finally, animalists can reply to a vicious species of the ‘too many thinkers’ problem to which they are allegedly uniquely vulnerable. (shrink)

Voinea, Porsdam Mann and Earp’s article, ‘Digital Twins or AI SIMs?’, clarifies the terminology surrounding generative artificial intelligence (AI) systems that imitate individuals, proposing the concept of AI Simulation of an Individual Mind (AI SIM) to provide conceptual and ethical clarity. Building on this contribution, this commentary frames digital representations of individuals along a dynamic spectrum—from imitation, simulation, emulation to replication—that captures increasing technological sophistication and ethical complexity. Rather than offering a static taxonomy, this spectrum emphasises contextual nuance and adaptive, (...) human-centric data and AI governance. While AI SIMs describe what these systems are, a spectrum-oriented approach helps illuminate what they may become and how they should be governed. (shrink)

Digital twinning in medicine refers to the idea of simulating a person’s organs, muscles or perhaps their entire body, in order to arrive more effectively at accurate diagnoses, to make treatment recommendations that reflect chances of success and possible side-effects, and to better understand the long-term trajectory of an individual’s overall condition. Digital twins, in these ways, build on the recent movement toward personalised medicine,1 and they undoubtedly present us with exciting opportunities to advance our health. Of course, the (...) opportunities are accompanied by newfound challenges—a common refrain in discussions surrounding emerging technologies. In a recent article, Matthias Braun surveys numerous problems, including the precision of simulations, ownership and consent to the use of digital models, and issues of justice in assuring equitable access to novel medical systems.2 In particular, he places special emphasis on the notion of representation. According to Braun, proper representation naturally calls for correspondence—namely a precise model offering dynamic, real-time feedback as well as transparency, both for the patient and the practitioner, in terms of the data being employed. While technical challenges remain, these goals are quite clear and relatively uncontroversial. Where a host of questions arise, however, is in the discussion on the interaction between the represented persons and their simulations. Alongside questions regarding ownership of one’s digital twin, Braun raises the concern that ‘giving …. (shrink)

A presentation and analysis of the twin-earth thought experiments.

In special cases of partial twinning, two heads, each supporting a more-orless normal human mental life, emerge from a single torso. It is often argued that there must be two people in such a case, even if there is only one biological organism. That would pose a problem for ‘animalism’, the view that people are organisms. The paper argues that it is very hard to say what sort of non-organisms the people in such cases would be. Reflection on partial (...) twinning is no more comfortable for those who think we’re not organisms than for those who think we are. We may have to accept that a single person could have two separate mental lives. (shrink)

The aim of this article is twofold: First, it is argued that Tyler Burge’s case for externalism in the philosophy of mind, which is based on Hilary Putnam’s twin-earth thought experiment, fails. Second, it is shown that a convincing argument for externalism can be nonetheless construed by relying on Putnam’s thought experiment.

Robust road surface estimation is required for autonomous ground vehicles to navigate safely. Despite it becoming one of the main targets for autonomous mobility researchers in recent years, it is still an open problem in which cameras and LiDAR sensors have demonstrated to be adequate to predict the position, size and shape of the road a vehicle is driving on in different environments. In this work, a novel Convolutional Neural Network model is proposed for the accurate estimation of the roadway (...) surface. Furthermore, an ablation study has been conducted to investigate how different encoding strategies affect model performance, testing 6 slightly different neural network architectures. Our model is based on the use of a Twin Encoder–Decoder Neural Network (TEDNet) for independent camera and LiDAR feature extraction and has been trained and evaluated on the Kitti–Road dataset. Bird’s Eye View projections of the camera and LiDAR data are used in this model to perform semantic segmentation on whether each pixel belongs to the road surface. The proposed method performs among other state-of-the-art methods and operates at the same frame rate as the LiDAR and cameras, so it is adequate for its use in real-time applications. (shrink)

This article explores the philosophical parallels between Plato’s theory of Perfect Forms and the modern concept of digital twins—virtual replicas of physical objects, systems, or processes. In Plato’s philosophy, the physical world is seen as an imperfect reflection of a higher realm of ideal, immutable Forms. Similarly, digital twins offer a dynamic, data-driven representation that often surpasses the accuracy and functionality of their physical counterparts. By continuously updating with real-time information, digital twins aim to create a “more perfect” version of (...) reality, challenging our traditional understanding of physical and virtual worlds. This article investigates whether digital twins achieve Plato’s vision of idealized perfection or represent a new, evolving form of idealism in the digital age, raising important questions about the nature of reality, truth, and the ongoing pursuit of optimization in both the physical and virtual realms. (shrink)

Fetal reduction is the practice of reducing the number of fetuses in a multiple pregnancy, such as quadruplets, to a twin or singleton pregnancy. Use of assisted reproductive technologies increases the likelihood of multiple pregnancies, and many fetal reductions are done after in vitro fertilisation and embryo transfer, either because of social or health-related reasons. In this paper, I apply Joe Horton’s all or nothing problem to the ethics of fetal reduction in the case of a twin pregnancy. I argue (...) that in the case of a twin pregnancy, there are two intuitively plausible claims: abortion is morally permissible, and it is morally wrong to abort just one of the fetuses. But since we should choose morally permissible acts rather than impermissible ones, the two claims lead to another highly implausible claim: the woman ought to abort both fetuses rather than only one. Yet, this does not seem right. A plausible moral theory cannot advocate such a pro-death view. Or can it? I suggest ways to solve this problem and draw implications for each solution. There are no data in this work. (shrink)