Philosophy professor, humorist, and identical twin Helena de Bres takes the curious, wondrous, ludicrous experience of being a twin as a lens through which to reconsider our place in the world and how we relate to others. Which one are you? Are you the same? Can you read each other's minds? Identical twins get the weirdest existential questions from strangers, also from loved ones, in fact, even from themselves. For twins fascinate all of us... including (...) class='Hi'>twins. For Helena de Bres, this fascination was never far from philosophy's most unnerving unknowns. What makes someone themselves rather than someone else? What does perfect love look like? Can we really act freely? Drawing from her relationship with her own twin Julia, and accompanied by Julia's line drawings, Helena uses twinhood to rethink the limits of personhood, consciousness, love, freedom, even justice. With her inimitably candid, goofy, brilliant voice, she explores the long tradition of twin representations in art, myth, and popular culture; their "freakish" history; their peculiar social standing; and what it's really like to be one of two. With hope and humor, she argues that our reactions to twins reveal our broader desires and fears about selfhood, fate, and human connection, and that reflecting on twinhood can help each of us-twin and singleton alike-to recognize our own multiplicity, and approach life with greater curiosity, imagination, and courage. (shrink)

We recapitulate (Section 1) some basic details of the system of implicative BCSK logic, which has two primitive binary implicational connectives, and which can be viewed as a certain fragment of the modal logic S5. From this modal perspective we review (Section 2) some results according to which the pure sublogic in either of these connectives (i.e., each considered without the other) is an exact replica of the material implication fragment of classical propositional logic. In Sections 3 and 5 we (...) show that for the pure logic of one of these implicational connectives two – in general distinct – consequence relations (global and local) definable in the Kripke semantics for modal logic turn out to coincide, though this is not so for the pure logic of the other connective, and that there is an intimate relation between formulas constructed by means of the former connective and the local consequence relation. (Corollary 5.8. This, as we show in an Appendix, is connected to the fact that the ‘propositional operations’ associated with both of our implicational connectives are close to being what R. Quackenbush has called pattern functions.) Between these discussions Section 4 examines some of the replacement-of-equivalents properties of the two connectives, relative to these consequence relations, and Section 6 closes with some observations about the metaphor of identical twins as applied to such pairs of connectives. (shrink)

We recapitulate (Section 1) some basic details of the system of implicative BCSK logic, which has two primitive binary implicational connectives, and which can be viewed as a certain fragment of the modal logic S5. From this modal perspective we review (Section 2) some results according to which the pure sublogic in either of these connectives (i.e., each considered without the other) is an exact replica of the material implication fragment of classical propositional logic. In Sections 3 and 5 we (...) show that for the pure logic of one of these implicational connectives two-in general distinct-consequence relations (global and local) definable in the Kripke semantics for modal logic turn out to coincide, though this is not so for the pure logic of the other connective, and that there is an intimate relation between formulas constructed by means of the former connective and the local consequence relation. (Corollary 5.8. This, as we show in an Appendix, is connected to the fact that the 'propositional operations' associated with both of our implicational connectives are close to being what R. Quackenbush has called pattern functions.) Between these discussions Section 4 examines some of the replacement-of-equivalents properties of the two connectives, relative to these consequence relations, and Section 6 closes with some observations about the metaphor of identical twins as applied to such pairs of connectives. (shrink)

Human cognition and action are intentional and goal-directed, and explaining how they are controlled is one of the most important tasks of the cognitive sciences. After half a century of benign neglect this task is enjoying increased attention. Unfortunately, however, current theorizing about control in general, and the role of consciousness for/in control in particular, suffers from major conceptual flaws that lead to confusion regarding the following distinctions: automatic and unintentional processes, exogenous control and disturbance of endogenous control, conscious control (...) and conscious access to control, and personal and systems levels of analysis and explanation. Only if these flaws are overcome will a comprehensive understanding of the relationship between consciousness and control emerge. (shrink)

Barbey & Sloman's (B&S's) base-rate respect model is anticipated by Reyna's denominator neglect model. There are parallels at three levels: (a) explanations are grounded in a general cognitive theory (rather than in domain-specific ideas); (b) problem structure is treated as a key source of reasoning errors; and most importantly, (c) nested set relations are seen as the cause of base-rate neglect.

During the first 16 days after fertilization, the developing embryo has the capacity to separate into two genetically identical embryos, or monozygotic twins (triplets, etc.). Because of this capacity, philosophers typically argue that the pre-16 day embryo is not a human being. On a Biological Account of Personal Identity (BAPI), which considers us human beings as essentially organisms, the development of the embryo into an organism at 16 (or 21) days marks our origins. The development of an embryo (...) into an organism is also said to mark the point at which the embryo loses its potential to give rise to monozygotic twins. This is considered a strength of the Biological account of our origins. I will argue here that it is the BAPI's own criteria that will have to allow cases of monozygotic twinning occurring even after 16 days, and that in virtue of this a Biological Account faces twinning puzzles usually reserved for earlier accounts of our origins. (shrink)

The author reviews one of the more intriguing articles in the stem cell research issue of the journal Metaphilosophy (April 2007), “Killing Embryos for Stem Cell Research,” by Jeff McMahan. He begins by recapitulating McMahan’s argument against the proposition that we are essentially individual human organisms. He then turns to two main critiques of the argument. First, he shows that the term “essentially” is insufficiently defined by McMahan and, more important, if we take the typical explication of the concept by (...) modal metaphysicians, then the claim “we are essentially human beings” is true—contrary to McMahan’s argument. Second, the author offers a counterexample to McMahan’s implicit acceptance of the principle that only beings who have developed the capacity for self-consciousness are the proper subjects of moral worth. The author presents a regenerative therapy example to show that McMahan’s commitment on this point is counterintuitive. National Catholic Bioethics Quarterly 8.2 (Summer 2008): 255–264. (shrink)

The folklore studies scholar, such as Dorson, was emphatic about the distinction between folklore and ‘fake lore’, one being authentic and the other as invented by the popular industry; however, he paradoxically maintained interest in the contemporariness of folklore. This was a paradox since the contemporariness of folklore is largely, and usually, due to intersections of folk with popular and political. Nevertheless, the emphasis on contemporariness was a harbinger of discussion on the potential dynamics of (...) class='Hi'>folklore, and everything buried therein, including value orientation. This essay is guided by the observations emerging from folklore studies, socio-cultural anthropology and performance studies in order to get into a specific case of Bihu, a folk performance inclusive of songs, dance, attires and instruments inter alia in Assam, in the northeast of India. The curious case of Bihu in flux divulges dynamics of value orientation and intersections of identity politics, in the wake of the contemporariness of folklore. (shrink)

Parthenogenesis is a form of asexual reproduction in which a gamete (ovum or sperm) develops without being fertilized. Tomer Jordi Chaffer uses parthenogenesis to challenge Don Marquis' future-like-ours (FLO) argument against abortion. According to Marquis, (1) what makes it morally wrong to kill us is that it would deprive us of a possible future that we might come to value—a future “like ours” (FLO) and (2) human fetuses are numerically identical to any adult human organism they may develop into, (...) and thus have a FLO. Chaffer contends that if human ova are capable of parthenogenesis, then they would have a FLO, which contraception may deprive them of, but contends this is absurd. Bruce P. Blackshaw challenges Chaffer, contending sexually fertilized embryos are not identical to unfertilized ovum, but this would yield a more absurd implication, that fertilization deprives an ovum of a FLO! Here I show Marquis' account of identity rules out both Chaffer's and Blackshaw's accounts. (shrink)

In explicating his version of the Organism View, Eric Olson argues that you begin to exist only after twinning is no longer possible and that you cannot survive a process of inorganic replacement. Assuming the correctness of the Organism View, but pace Olson, I argue in this paper that the Organism View does not require that you believe either proposition. The claim I shall make about twinning helps to advance a debate that currently divides defenders of the Organism View, while (...) the claim I shall make about inorganic replacement will help to put the Organism View on a par with its rival views by allowing it to accommodate a plausible intuition that its rivals can accommodate, namely, the intuition that you can survive a process of inorganic replacement. Both claims, I shall also argue, are important for those who are interested in the identity condition of a human organism, even if they do not hold the view that you are essentially an organism. (shrink)

Michael Scriven’s (1959) example of identical twins (who are said to be equal in fitness but unequal in their reproductive success) has been used by many philosophers of biology to discuss how fitness should be defined, how selection should be distinguished from drift, and how the environment in which a selection process occurs should be conceptualized. Here it is argued that evolutionary theory has no commitment, one way or the other, as to whether the twins are equally (...) fit. This is because the theory of natural selection is fundamentally about the fitnesses of traits, not the fitnesses of token individuals. A plausible philosophical thesis about supervenience entails that the twins are equally fit if they live in identical environments, but evolutionary biology is not committed to the thesis that the twins live in identical environments. Evolutionary theory is right to focus on traits, rather than on token individuals, because the fitnesses of token organisms (as opposed to their actual survivorship and degree of reproductive success) are almost always unknowable. This point has ramifications for the question of how Darwin’s theory of evolution and R. A. Fisher’s are conceptually different. (shrink)

We examine the philosophical and ethical issues associated with conjoined twins and their surgical separation. In cases in which there is an extensive sharing of organs, but nevertheless two distinguishable functioning brains, there are a number of philosophical and ethical challenges. This is because such conjoined twins: 1. give rise to puzzles concerning our identity, about whether we are identical to something psychological or biological;2. force us to decide whether what matters from an ethical point of view (...) is the biological life of our organisms or the existence of our consciousness or mind; 3. raise questions concerning when, if ever, it is morally acceptable to sacrifice one of us to save another;4. force us to reflect on the conditions for ownership of organs and the justification of removal of organs for transplantation which causes the death of the donor; 5. raise questions about who should take decisions about life-risking treatments when this cannot be decided by patients themselves.We examine and suggest answers to these questions. (shrink)

Over the last decade, the international media has devoted increasing attention to operations that separate conjoined twins. Despite the fairly low odds that a child or adult will survive the operation with all of their vital organs intact, most people fail to question the urgency of being physically separated from one’s identical twin. The drive to surgically tear asunder that which was originally joined, I suggest, is motivated in part by a refusal to acknowledge intercorporeality as a basic (...) condition of human existence that doesn’t undermine identity but makes it possible in the first place. (shrink)

In a series of articles, Terry Horgan and Mark Timmons have argued that Richard Boyd’s defence of moral realism, utilizing a causal theory of reference, fails. Horgan and Timmons construct a twin Earth-style thought experiment which, they claim, generates intuitions inconsistent with the realist account. In their thought experiment, the use of (allegedly) moral terms at a world is causally regulated by some property distinct from that regulating their use here on Earth; nevertheless, Horgan and Timmons claim, it is intuitive (...) that the inhabitants of this world disagree with us in their moral claims. Since any disagreement would be merely verbal were the alleged moral facts identical to or constituted by different natural facts, the identity or constitution claim must be false. I argue that their argument fails. Horgan and Timmons’ thought experiment is underdescribed; when we fill out the details, I claim, we shall see that the challenge to moral realism fades away. I sketch two possible interpretations of the (apparently) moral claims of the inhabitants of moral Twin Earth. On one interpretation, they fail to disagree with us because they actually agree with us; on the other, they fail to disagree with us because they are not moralizers at all. Which interpretation is true, I argue, will depend on the facts that explain the differences between us and the inhabitants of moral twin Earth. (shrink)

The view that human beings begin to exist at fertilization (namely conceptionism) faces a serious challenge from the twinning argument, that identical twins coming from the same zygote must be numerically distinct from the zygote and so did not exist at fertilization. Recently, some philosophers have claimed that the twinning argument rests on a particular metaphysical theory of persistence, namely endurantism, on which a human being, for example, is wholly present at every moment of her existence. And we (...) can easily refute the argument, they claim, by employing perdurantism or exdurantism, according to which a human being is a temporally extended entity with temporal parts or a momentarily existing stage who has other momentarily existing stages as counterparts. I argue that such claims are mistaken. The twinning argument does not rest on endurantism and can be formulated in terms of perdurantism to provide a good reason for perdurantists to reject conceptionism. And exdurantism does not have any advantage in defending conceptionism either, for it already concedes more than what the twinning argument aims to show. (shrink)

Various cases of conjoined twinning have been presented as problems for the animalist view that we are animals. In some actual and possible cases of human dicephalus that have been discussed in the literature, it is arguable that there are two persons but only one human animal. It is also tempting to believe that there are two persons and one animal in possible instances of craniopagus parasiticus that have been described. Here it is argued that the animalist can admit that (...) these are cases in which human persons are not animals, without forfeiting the title “animalist.” It is also shown that this is not only an option but also a well-motivated and plausible option for the animalist. Seeing this requires getting clear on what the word “we” should be thought to include in the animalist's claim that we are animals. Here animalism is defended against twinning objections by figuring out how to view the scope of the animalist's identity claim. (shrink)

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)

A common concern with respect to cloning is based on the belief that cloning produces identical individuals. This is a fundamental misunderstanding of what type of identity-relation cloning involves. The concept "identity" is ambiguous, and the statement that cloning produces "identical" individuals is not meaningful unless the notion of identity is clarified. This paper distinguishes between numerical and qualitative; relational and intrinsic; logical and empirical identity, and discusses the empirical individuation of clones in terms of genetics, physiology, perception, (...) cognition and personality. I argue that the only relation of identity cloning involves is qualitative, intrinsic and empirical: genetic indiscernibility , unlikely to include identity under other aspects mentioned. A popular argument against cloning claims our "right" to a "unique identity". This objection either implies (absurdly) the right not to be an identical twin, or assumes (incorrectly) that cloning involves identity other than genetic. Either way, the argument is untenable. (shrink)

In a 1911 research manuscript, Husserl puts forth an idea that resembles Putnam’s Twin Earth thought experiment presented in the 1970s. In this paper, I study Husserl’s “Twin Earth” passage and assess various readings of it to determine whether Husserl is better understood as an internalist or an externalist. I define internalism as the view that content depends solely on internal factors to the subject, whereas I distinguish between two versions of externalism: weak externalism, according to which content can also (...) depend on other subjects’ conceptions, and strong externalism, which maintains that content can also depend on the real world. Only strong externalism maintains what McGinn calls “the philosophical significance of externalism” because it entails realism about the world. I argue that Husserl is better understood as an externalist when it comes to the “Twin Earth” passage, but the more precise question regarding weak and strong externalism requires further evidence. This additional evidence concerns Husserl’s concepts of the identity of sense (Sinnesidentität) and worldly meaning (weltlicher Sinn). In evaluating externalist Husserl interpretations, I classify Smith’s externalist interpretation as weak, whereas I take Crowell’s externalist interpretation to be ambivalent. Crowell’s excellent but somewhat embryonic interpretation leaves the dependence relation between content and the real world ambiguous. I clarify this relation by assessing McGinn’s argument for the philosophical significance of externalism from the Husserlian viewpoint. Although this study is historical, it also serves a systematic purpose because the externalist interpretation of Husserl calls into question central issues in phenomenology and externalism. (shrink)

Physicists Brian Greene and Max Tegmark both make variants of the claim that if the universe is infinite and matter is roughly uniformly distributed, then there are infinitely many “people with the same appearance, name and memories as you, who play out every possible permutation of your life choices.” In this paper I argue that--while our current best theories in astrophysics may allow one to conclude that we have infinitely many duplicates whose lives are identical to our own from (...) start to finish--without either further advances in physics or advances in fields like biology, psychology, neuroscience, and philosophy, Greene’s and Tegmark’s claims about the ways in which our duplicates lives will differ from our own are not a consequence of our best current scientific theories. Rather, I argue that Greene and Tegmark’s conclusions rely on philosophically imprecise usages of the language of “possibility.”. (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 contribution questions the positive/negative eugenics dichotomy that typifies the historiography on the eugenic movement in the Netherlands and the claim that this movement was mostly marginal because only positive eugenics was pursued. From 1938 to 1968 in the Netherlands, after a decade of debates, 400 sex offenders who had been committed to asylums for the criminally insane were ‘voluntarily’ and ‘therapeutically’ castrated. For political reasons debates on castration, meant to create consensus, eliminated any reference to or connotation with eugenics, (...) yet these policies were unthinkable without them. This article shows that thinking about social and sexual problems and their solutions in the 1930s were permeated by eugenic folklore which in turn was informed by sexual folklore. Both eugenic and sexual lore, as common sense, or as ways of knowing, were about individual and collective loss of self control which was referred to with a catch-all phrase: ‘hypersexuality’. Although sexual classifications used in diagnosing sex offenders suggested the existence of discrete sexual categories, homosexuality for instance was not seen as a sexual alternative or as an identity but as the extent to which an offender suffered from a form of hypersexuality that threatened the fabric of society. (shrink)

One day, when Krishna wanted to board an aeroplane, he was not allowed to! All because he did not have an identity card. Then his friends Garuda and Sesha took him to meet Lata-kumari in Guwahati, who told him the story of Anasuya and the Ashwini twins, and why Rishi Chavan made a rule that all gods should carry a dhvaja—a flag with each god’s very own symbol. Did Krishna get his identity card so he could ride the aeroplane (...) finally? o Why are identity cards important, even for gods? o How can you tell a Deva from a Manava? o How would you find a particular god in a crowd of gods? (shrink)

In this paper, we present a set of preregistered studies inspired by both Lockean pluralism about individuation and discussions of conjoined twinning in the contemporary personal identity debate. In combination, these studies provide evidence of folk pluralism about individuation of “individuals like us” and also ways in which individuation judgments are integral to practical interests. First, our studies show that individuation judgments depend on a sortal supplied. Study participants tend to see two people or persons but only one organism in (...) case of dicephalic twins, and they do not find these two verdicts inconsistent. Second, study participants tend to be pluralist in a sense that they find it acceptable to consider dicephalic twins to be—at the same time—two persons sharing one body and one two‐headed person. Third, while both perspectives are available, when reasons for counting are made salient, study participants tend to resolve pluralism in line with practical interests relevant in the context. (shrink)

Feminist analyses of gender concepts must avoid the inclusion problem, the fault of marginalizing or excluding some prima facie women. Sally Haslanger’s ‘ameliorative’ analysis of gender concepts seeks to do so by defining woman by reference to subordination. I argue that Haslanger’s analysis problematically marginalizes trans women, thereby failing to avoid the inclusion problem. I propose an improved ameliorative analysis that ensures the inclusion of trans women. This analysis yields ‘twin’ target concepts of woman, one concerning gender as class and (...) the other concerning gender as identity, both of which I hold to be equally necessary for feminist aims. (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)

Are embryos deserving of moral consideration in our actions? A standard view suggests that embryos are considerable only if they have interests. One argument for embryonic interests contends that embryos are harmed by death because they are deprived of valuable future lives as adult persons. Some have challenged this argument on the grounds that embryos aren’t identical to adults: either due to the potential for embryos to twin or because we do not exist until the fetus develops consciousness. These (...) arguments fail to show that embryos do not have future adult lives. There is a better reason to think that embryos cannot have interests; namely, because they are not capable of having desires. Others have held this view but have not sufficiently justified it. The justification lies in the fact that the capacity for desires is necessary to make sense of the normativity of interests. (shrink)

At the beginning of the twentieth century, G. E. Moore’s open question argument convinced many philosophers that moral statements were not equivalent to statements made using non- moral or descriptive terms. For any non- moral description of an object or object it seemed that competent speakers could without confusion doubt that the action or object was appropriately characterized using moral terms such as ‘good’ or ‘right’. The question of whether the action or object so described was good or right was (...) always open, even to competent speakers. In the absence of any systematic theory to explain the possibility of synthetic as opposed to analytic identities, many were convinced this demonstrated that moral properties could not be identified with any natural properties. Thus Moore and others concluded that moral properties such as goodness were irreducible sui generis properties, not identical to natural. (shrink)

‘Semantic externalism’ is the view that the thought and speech of internally identical subjects can have different contents, depending on facts about their environments. ‘Semantic internalism’ is the negation of this view. The details of these two views depend on the definition of ‘internal identity’. Katalin Farkas has shown that the traditional definition of internal identity as physical identity is too permissive: it misclassifies certain bodily states as internal. She has proposed defining internal identity as phenomenal identity instead. In (...) the critical part of my paper, I argue that Farkas’s proposal fails for being too restrictive: it misclassifies non-conscious mental states, most notably dispositional belief, as external. I consider two interpretations of Farkas’s proposal but conclude that neither succeeds, because each requires internal features to influence the subject’s phenomenal life in a way in which dispositional belief does not. In the constructive part of my paper, I consider dispositional identity as an alternative definition of internal identity. I argue that the dispositional-identity definition avoids the phenomenal-identity definition’s shortcoming and retains its main attraction, viz., that of securing the subjective indistinguishability that obtains between Twin Earth duplicates. My argument that it does the latter, however, faces potentially decisive obstacles. Thus, I retreat to a disjunctive proposal: internal identity should be defined either as dispositional identity or as dispositional-plus-phenomenal identity. I conclude by defending my proposal against a different charge that may be levelled against it, viz., that of misclassifying Cartesian dualism as an externalist theory of the mind. (shrink)

Given research and public interest for conditions related to an extended lifespan, we addressed the questions of what matters and what matters most for subsequent survival past age 80. The data was drawn from the population-based and multidisciplinary Swedish OCTO Twin Study, in which a sample consisting of identical and same-sex fraternal twin pairs, followed from age 80 until death, provided detailed data on health, physical functioning, life style, personality, and sociodemographic conditions. Information concerning date of birth and death (...) were obtained from population census register. We estimated heritability using an ACE model and evaluated the role of multiple predictors for the mortality-related hazard rate using Cox regression. Our findings confirmed a low heritability of 12%. As expected, longer survival was associated with being a female, an apolipoprotein E e4 allele non-carrier, and a non-smoker. Several diseases were found to be associated with shorter survival as well as certain health conditions. Stronger grip and better lung function, as well as better vision, and better cognitive function was related to longer survival. Social embeddedness, better self-evaluated health, and life-satisfaction were also significantly associated with longer survival. After controlling for the impact of comorbidity, functional markers, and personality-related predictors, we found that sex, cerebrovascular diseases, compromised cognitive functioning, self-related health, and life-satisfaction remained as strong predictors. Cancer was only associated with the mortality hazard when accounting for other co-morbidities. The survival estimates were mostly in anticipated directions and contained effect sizes within the expected range. Noteworthy, we found that some of the so-called “soft-markers” remained strong predictors, despite a control for other factors. For example, self-evaluation of health and ratings of life-satisfaction provide additional and valuable information. (shrink)

In this paper, the arguments against the mind-body identity thesis from the author’s [1994] paper, “Mental Properties,” are presented but in significantly more detail. It is shown that, because of scientific essentialism, two currently popular arguments against the identity thesis -- the multiple-realizability argument and the Nagel-Jackson knowledge argument -- are unsatisfactory as they stand and that their problems are incurable. It is then shown that a refutation of the identity thesis in its full generality can be achieved by weaving (...) together two traditional Cartesian arguments -- the modal argument and the certainty argument. This argument establishes, not just the falsity of the identity thesis, but also the metaphysical possibility of disembodiment. The paper ends with a discussion of the nature of the relation between the mind and the body. (shrink)

This paper intends to invoke the spirit of Hegel as the éminence grise behind analytical and continental philosophy. Both movements can be seen to originate in, or to receive a strong impetus in their development from, a repudiation of Hegel. Even Russell's quest for a systematic logical analysis of language may be seen as an attempt at a quasi- or anti-Hegelian systematicity. The collapse of this systematicity has led to the celebration of difference in both the analytical and continental schools. (...) Another feature of contemporary philosophy is the priority given to invention and creativity over discovery. In this respect, Nietzsche is the master-figure underlying all contemporary allegiance to, and indeed, obsession with, the twin idols of creation and difference. (shrink)

In a recent paper, Chunghyoung Lee argues that, because zygotes are developmentally plastic, they cannot be numerically identical to the singletons into which they develop, thereby undermining conceptionism. In this short paper, I respond to Lee. I argue, first, that, on the most popular theories of personal identity, zygotic plasticity does not undermine conceptionism, and, second, that, even overlooking this first issue, Lee’s plasticity argument is problematic. My goal in all of this is not to take a stand in (...) the abortion debate, which I remain silent on here, but, rather, to push for the conclusion that transitivity fails when we are talking about numerical identity of non-abstract objects. (shrink)