Nicholas Rescher has argued we must tolerate inconsistency because of our cognitive limitations. He has also produced, together with R. Brandom, a serious attempt at exploring the logic of inconsistency. Inconsistency tolerance calls for a systematic rewriting of our logical doctrines: it requires a paraconsistent logic. However, having given up all aggregation of premises, Rescher's proposal for a paraconsistenl logic fails to account for the reductive reasoning Rescher appeals to in his account of inconsistency tolerance. A non-adjunctive logic developed by (...) P.K. Schotch and RE. Jennings provides just what Rescher's logic is lacking: It allows a tolerant attitude toward inconsistency while giving an account of reductive reasoning. (shrink)

Don Marquis' future‐like‐ours account is regarded as the best secular anti‐abortion position because he frames abortion as a wrongful killing via deprivation of a valuable future. Marquis objects to the reductio ad absurdum of contraception as being immoral because it is too difficult to identify an individual that is deprived of a future. To demonstrate why Marquis’ treatment of the contraception reductio is flawed by his own future‐like‐ours line of reasoning, I offer an argument for why there is (...) indeed a candidate for harm—the ovum—for it can be viewed as providing the functional foundation for a new life through (1) mitochondrial DNA inheritance, (2) paternal histone restructuring during fertilization, and (3) ability to initiate parthenogenesis. As evidenced by these distinct and natural features of ova, candidate (2) “some ovum or other” should be morally prioritized as the direct candidate for harm in the contraception reductio. By assessing the philosophical inconsistencies in Marquis’ future‐like‐ours argument, this paper provides strong metaphysical grounds for rejecting the best secular anti‐abortion position. (shrink)

We introduce a novel expansion of the four-valued Belnap–Dunn logic by a unary operator representing reductio ad contradictionem and study its algebraic semantics. This expansion thus contains both the direct, non-inferential negation of the Belnap–Dunn logic and an inferential negation akin to the negation of Johansson’s minimal logic. We formulate a sequent calculus for this logic and introduce the variety of reductio algebras as an algebraic semantics for this calculus. We then investigate some basic algebraic properties of this (...) variety, in particular we show that it is locally finite and has EDPC. We identify the subdirectly irreducible algebras in this variety and describe the lattice of varieties of reductio algebras. In particular, we prove that this lattice contains an interval isomorphic to the lattice of classes of finite non-empty graphs with loops closed under surjective graph homomorphisms. (shrink)

The present article contains part of results from my lecture delivered at II Flemish-Polish workshop on Ontological Foundation of Paraconsistency.

The uses and interpretation of reductio ad absurdum argumentation in mathematical proof and discovery are examined, illustrated with elementary and progressively sophisticated examples, and explained. Against Arthur Schopenhauer’s objections, reductio reasoning is defended as a method of uncovering new mathematical truths, and not merely of confirming independently grasped mathematical intuitions. The application of reductio argument is contrasted with purely mechanical brute algorithmic inferences as an art requiring skill and intelligent intervention in the choice of hypotheses and attribution (...) of contradictions deduced to a particular assumption in a contradiction’s derivation base within a reductio proof structure. (shrink)

Used informally, the Reductio ad Absurdum (RAA) consists in reasoning appealing to the logically implied, absurd consequences of a hypothetical proposition, in order to refute it. This kind of reasoning resembles the Argument from Consequences, which appeals to causally induced consequences. These types of argument are sometimes confused, since it is not worked out how these different kinds of consequences should be distinguished. In this article it is argued that the logical consequences in RAA-argumentation can take different appearances and (...) that it therefore must be concluded that RAA cannot be characterised by a specific content, but must instead be characterised as an argument form. Furthermore, clues are provided to distinguish RAA reasoning from the Argument from Consequences. (shrink)

In the Organon Aristotle describes some deductive schemata in which inconsistencies do not entail the trivialization of the logical theory involved. This thesis is corroborated by three different theoretical topics by him discussed, which are presented in this paper. We analyse inference schema used by Aristotle in the Protrepticus and the method of indirect demonstration for categorical syllogisms. Both methods exemplify as Aristotle employs classical reductio ad absurdum strategies. Following, we discuss valid syllogisms from opposite premises (contrary and contradictory) (...) studied by the Stagerian in the Analytica Priora (B15). According to him, the following syllogisms are valid from opposite premises, in which small Latin letters stand for terms such as subject and predicate, and capital Latin letters stand for the categorical propositions such as in the traditional notation: (i) in the second figure, Eba,Aba ` Eaa (Cesare), Aba, Eba ` Eaa (Camestres), Eba, I ba ` Oaa (Festino), and Aba,Oba ` Oaa (Baroco); (ii) in the third one, Eab,Aab ` Oaa (Felapton), Oab,Aab ` Oaa (Bocardo) and Eab, Iab ` Oaa (Ferison). Finally, we discuss the passage from the Analytica Posteriora (A11) in which Aristotle states that the Principle of Non-Contradiction is not generally presupposed in all demonstrations (scientific syllogisms), but only in those in which the conclusion must be proved from the Principle; the Stagerian states that if a syllogism of the first figure has the major term consistent, the other terms of the demonstration can be each one separately inconsistent. These results allow us to propose an interpretation of his deductive theory as a broad sense paraconsistent theory. Firstly, we proceed to a hermeneutical analysis, evaluating its logical significance and the interplay of the results with some other points of Aristotle’s philosophy. Secondly, we point to a logical interpretation of the Aristotelian syllogisms from opposite premises in the antilogisms method proposed by Christine Ladd-Franklin in 1883, and we also present a logical treatment of the Aristotelian demonstration with inconsistent material in the paraconsistent logics Cn, 1 _ n _!, introduced by da Costa in 1963. These two issues seem having not yet been analysed in detail in the literature. (shrink)

Most serious contemporary opposition to abortion is grounded on the belief that human fetuses are members of the same moral category as beings like us, and that the loss of any such life is one of the worst possible losses. Substance view theorists oppose abortion for this reason: in their view beings like us are essentially rational substances with inherent moral worth, and those who perform induced abortion fail to recognize this moral worth. In a recent series of articles, Rob (...) Lovering presents reductio‐style arguments against the substance view, in part arguing that it is inconsistent with our intuitions in rescue and spontaneous abortion cases. In a recent reply, Henrik Friberg‐Fernros argues that the substance view can evade these problematic implications because of a distinction between killing and letting die. According to this argument, the fetus’s right to life is a negative right not to be killed, not a positive right to be rescued, thus the anti‐abortion theorist who lets fetuses die acts acceptably. I argue this stance fails to recognize the inherent moral worth that the substance view contends fetuses possess. One who refrains from saving a person, or doesn’t care how many people she saves, cannot reasonably claim to value life. Furthermore, this stance is at odds with most contemporary anti‐abortion views that oppose induced abortions of both the killing and letting die variety. (shrink)

It is well known that reductio ad absurdum arguments raise a number of interesting philosophical questions. What does it mean to assert something with the precise goal of then showing it to be false, i.e. because it leads to absurd conclusions? What kind of absurdity do we obtain? Moreover, in the mathematics education literature number of studies have shown that students find it difficult to truly comprehend the idea of reductio proofs, which indicates the cognitive complexity of these (...) constructions. In this paper, I start by discussing four philosophical issues pertaining to reductio arguments. I then briefly present a dialogical conceptualization of deductive arguments, according to which such arguments are best understood as a dialogue between two participants—Prover and Skeptic. Finally, I argue that many of the philosophical and cognitive difficulties surrounding reductio arguments are dispelled or at least further clarified once one adopts a dialogical perspective. (shrink)

Most scientific theories are globally inconsistent. Chunk and Permeate is a method of rational reconstruction that can be used to separate, and identify, locally consistent chunks of reasoning or explanation. This then allows us to justify reasoning in a globally inconsistent theory. We extend chunk and permeate by adding a visually transparent way of guiding the individuation of chunks and deciding on what information permeates from one chunk to the next. The visual representation is in the form of bundle diagrams. (...) We then extend the bundle diagrams to include not only reasoning in the presence of inconsistent information or reasoning in the logical sense of deriving a conclusion from premises, but more generally reasoning in the sense of trying to understand a phenomenon in science. This extends the use of the bundle diagrams in terms of the base space and the fibres. We then apply this to a case in physics, that of understanding binding energies in the nucleus of an atom using together inconsistent models: the liquid drop model and the shell model. We draw some philosophical conclusions concerning scientific reasoning, paraconsistent reasoning, the role of logic in science and the unity of science. (shrink)

Despite the fact that the reductio ad absurdum argument is a valid deductive form, while the slippery slope argument is most often presented as a fallacious form of inductive argument, the two argument types bear some striking similarities. Investigation of these similarities reveals some more universal difficulties in the teaching of informal logic, and, in particular the difference between strong informal arguments and fallacious ones.

In this paper, I present an argument to show that the doctrine of divine temporality (the view that God is in time, but everlastingly eternal) is incoherent. The doctrine of divine temporality entails that God has traversed an actually infinite series of moments in order to reach the present. But I show that an actually infinite series of moments cannot be traversed. Hence, God could not have traversed his infinite past to reach the present. Therefore, the doctrine of divine temporality (...) is necessarily false. I defend this argument against various responses and objections. (shrink)

Theists believe that God is eternal, but they differ as to just what God's eternality means . The traditional, historic view of most Christian philosophers is that eternality means that God is timeless. He is ‘outside’ of time and not subject to any kind of temporal change. Indeed, God is the creator of time. Lets call this view divine timelessness.

As Federal Indian Law has evolved, many questions have been posed regarding tribal jurisdiction. This paper examines the jurisdiction tribes have over member Indians, non-member Indians, and non-member, non-Indians. It addresses the ethical challenge faced by tribal attorneys who represent non-member Indian clients in a manner that ultimately undermines tribal sovereignty.

Ibn Sīnā proposed an analysis of arguments by reductio ad absurdum. His analysis contains, perhaps for the first time, a workable method for handling the making and discharging of assumptions in a formal proof. We translate the relevant text of Ibn Sīnā and put his analysis into the context of his general approach to logic.

Considerando que o cogito possa ser tomado, nas Meditações, como uma conclusão de uma demonstração, pode-se avançar a tese de que essa demonstração está consoante ao método analítico, que Descartes reconhece empreender nesse texto. Esse método teria entre as suas funções nas Meditações aquela de apresentar – sob a forma de uma rede de implicações ontológicas – o raciocínio que conduz à certeza da existência. Como cumpre no referido texto determinar a certeza da existência sem tomar como base nenhuma certeza (...) preestabelecida, o método analítico financiaria, segundo a nossa interpretação, uma reconstrução do argumento do cogito sob uma base indireta, mais precisamente através de uma reductio ad absurdum, cujo objetivo consiste em mostrar a contradição inelutável que surge na tentativa de um indivíduo de provar a sua não existência. (shrink)

Considerando que o cogito possa ser tomado, nas Meditações, como uma conclusão de uma demonstração, pode-se avançar a tese de que essa demonstração está consoante ao método analítico, que Descartes reconhece empreender nesse texto. Esse método teria entre as suas funções nas Meditações aquela de apresentar – sob a forma de uma rede de implicações ontológicas – o raciocínio que conduz à certeza da existência. Como cumpre no referido texto determinar a certeza da existência sem tomar como base nenhuma certeza (...) preestabelecida, o método analítico financiaria, segundo a nossa interpretação, uma reconstrução do argumento do cogito sob uma base indireta, mais precisamente através de uma reductio ad absurdum, cujo objetivo consiste em mostrar a contradição inelutável que surge na tentativa de um indivíduo de provar a sua não existência. (shrink)

El Menón es un buen ejemplo del uso de la ironía socrática como forma de refutación. Específicamente, la forma lógica de reducción al absurdo constituye un dispositivo muy relacionado con la ironía socrática. En este artículo, se examinan analíticamente los cuatro elementos de la ironía que se presentan en el diálogo: 1. el conocimiento falso como una posición inicial asumida por los interlocutores de Sócrates; 2. la igno­ rancia socrática; 3. la reducción al absurdo del falso saber inicial; y 4. (...) el reconocimiento del error y la ignorancia. (shrink)

In this paper, I will demonstrate via reductio ad absurdum that a resolute reading of Wittgenstein’s Tractatus should reconsider their equation of “throwing away the ladder” with the “end of philosophy.” To do this, I will show that an inconsistency arises in Wittgenstein’s view regarding the relationship of philosophy and science since he associates “the correct method of philosophy” with the propositions of science at the end of the aforementioned text. Due to this, I will maintain that it is (...) reasonable to posit that the sharp distinction that Wittgenstein makes between philosophy and science in the Tractatus is merely illusory. An interesting consequence of this is that if this interpretation holds then this provides sufficient grounds to maintain that what some scholars refer to as “the end of philosophy” may actually be the beginning of “Wittgenstein’s naturalism.”. (shrink)

Too much rationalist social philosophy is polarized into radical and conservative factions, both seeking support for rival claims to intellectual authority. Moreover, each faction can raise what it sees as a valid critique of the other. To the uncommitted, this mutual critique presents a reductio ad absurdum of rationalism and invites violence and despair. The radicalist claim that a rationalist social philosophy is necessarily radical clashes with the conservative critique which sees radicalism demanding the impossible from reason. So the (...) question is whether this radical controversy between opposing rationalisms is amenable to rational resolution.This question is addressed through an examinalion of three writers: two radicals, Jean-Paul Sartre, who presents a comprehensive rationalism, and Herbert Marcuse, whose rationalism is irrationally grounded and authoritarian, and a conservative, Karl Popper, whose critique of comprehensive rationalism is effective against Sartre’s view, but whose own concession to irrationaIism unwittingly supports Marcuse’s approach.Yet, if Popper’s approach can be improved by abandoning both polarization and the exclusion of all radicalism, then we may have a rational social philosophy of a new non-authoritarian sort. The prospects for such a new approach are considered in the last section. (shrink)

Too much rationalist social philosophy is polarized into radical and conservative factions, both seeking support for rival claims to intellectual authority. Moreover, each faction can raise what it sees as a valid critique of the other. To the uncommitted, this mutual critique presents a reductio ad absurdum of rationalism and invites violence and despair. The radicalist claim that a rationalist social philosophy is necessarily radical clashes with the conservative critique which sees radicalism demanding the impossible from reason. So the (...) question is whether this radical controversy between opposing rationalisms is amenable to rational resolution.This question is addressed through an examinalion of three writers: two radicals, Jean-Paul Sartre, who presents a comprehensive rationalism, and Herbert Marcuse, whose rationalism is irrationally grounded and authoritarian, and a conservative, Karl Popper, whose critique of comprehensive rationalism is effective against Sartre’s view, but whose own concession to irrationaIism unwittingly supports Marcuse’s approach.Yet, if Popper’s approach can be improved by abandoning both polarization and the exclusion of all radicalism, then we may have a rational social philosophy of a new non-authoritarian sort. The prospects for such a new approach are considered in the last section. (shrink)

Pacifists imagine a “great peace,” to borrow a phrase from Martin Buber. This great peace will uphold justice and respect for humanity. It will not efface difference or negate liberty and identity. The great peace will be a space in which genuine dialogue can flourish—in which we can encounter one another as persons, listen to one another, embrace our common humanity, and acknowledge our differences. The great peace is much more than the absence of war. It is holistic, organic, dialogical, (...) and thick with human relation.The dream of the great peace runs aground on the reality of petty conflicts, dehumanizing institutions, selfishness, egoism, arrogance, murder, war, and psychopathology. While ordinary selfishness poses a mundane obstacle to the great peace, genocide appears to create a reductio ad absurdum argument against the dream of the great peace and against pacifism itself. Critics will argue that in extremis a pacifist would be either mad or immoral to remain committed to nonviolence. This idea has been explored by a number of critics who argue that pacifism is primarily for dreamers and idealists, who are not willing to do what is necessary to confront evil and atrocity in the real world.This paper argues that a moderate commitment to pacifism and nonviolence remains plausible despite the atrocity objection. Some may argue that the term “pacifism” is not applicable to a position that admits that there are exceptional cases in which violence can be justified. But as I have argued elsewhere, there are varieties of pacifism (Fiala, 2004; 2008; 2014a; 2014b). The type of pacifism described here is transformational or transformative pacifism. Transformational pacifism is not absolutist in its rejection of violence, even though it offers a comprehensive critique of violence that aims at creating the great peace by changing the way we think and talk about war, violence, and peace itself. Martin Buber is a good example of a transformational pacifist. He admitted that some form of violence could be justified (say, in response to the Holocaust). But his goal was not to justify violence—rather, he wanted to transform the world in order to prepare the way for the great peace. One important consideration here is that Buber is not primarily a political thinker or an applied ethicist: rather, he offers a metaphysical, religious, psychological, and cultural theory. Transformative pacifism is located at that higher level. It idealizes, speculates, and imagines. For this reason, critics might condemn it as utopian. But trans-formative pacifism remains inspiring and useful. (shrink)

Norman Finkelstein, a prominent political scientist specializing in the Palestine-Israel conundrum, on which he has authored five highly praised books, was denied tenure at DePaul University by the President, Rev. Dennis H. Holtschneider, on June 8, 2007. After examining the particulars of the case, it strikes me as so obviously wrong to deny him tenure that the tenure procedure at DePaul constitutes a reductio ad absurdum of a university system which allows such a thing to happen.

The ‘Private Language’ sections of the Philosophical Investigations §§ 243–315 serve to undermine the idea that our ordinary felt sensations, e.g., of heat, or cold, or pain, together with our experienced impressions of colour or of sound, are ‘private’ or ‘inner’ objects, where an object mirrors in the mental realm what we associate with that of the physical. This paper explores Wittgenstein's method in these sections, together with the work of several of his commentators who agree with his ‘therapeutic’ approach (...) to the denial of a possible private language. More significantly, however, it discovers a paradox in the fact that a number of philosophers who claim that his ‘Argument Against Private Language’ is unsuccessful point in reaching this conclusion to the very features concerning first-person sensation ascription that Wittgenstein employs to reveal that our ordinary sensations are not ‘private’ to us in that sense identified in § 243, which talks of ‘a language used to refer to what only its speaker can know’, viz, ‘his immediate private sensations’. This helps to explain why there is still no general agreement on the significance of §§ 243–315. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:The Philosophy of Bishop Stillingfleet RICHARD H. POPKIN EDWARD STILLINGFLEET(1635-1699), the Bishop of Worcester, is known only as Locke's opponent. Although he was a leading figure in seventeenth century intellectual history, he is now almost completely forgotten.1 He is only mentioned once in the Encyclopedia of Philosophy as the first person to write against Deism. 2 His texts have been ditlicult to locate, and have hardly been studied. Although (...) Locke's answers to him comprise a large volume in Locke's Works, little interest has been shown in Stillingfleet's side of the story. His letters to Locke were last printed in the 1710 edition of his works. (I am now publishing a photoreproduction edition of the attacks on Locke, and a photoreproduction of the six volumes of his works is due soon.) In spite of this neglect, Stillingfleet was a quite interesting figure. He was not a simple moss-back, a religious reactionary, fighting progressive theories like Locke's. Rather, he was trying to maintain some basis for religious belief in the face of the intellectual upheavals in the seventeenth century. For over forty years he struggled against a wide range of philosophical and theological developments of the time that he saw as leading to scepticism and infidelity. Stillingfleet attempted to defend the reasonableness of Christianity in an intellectual world dominated by the new science, the new philosophy, the religious wars, the rise of irreligion, Bible criticism, and Spinozism. In the new scientific, philosophical and theological context he sought to show how an intelligent, reasonable man could maintain his religious views as more probable than their denials. And, he tried to show the perils involved in various new lines of thought. As he wrote to Locke, "in an age wherein the Mysteries of Faith are so much exposed by the Promoters of Scepticism and Infidelity, it is a thing of dangerous consequence to start such new methods of Certainty as are apt to leave men's minds more doubtJull than before." 3 Stillingfleet criticized various new views of thinkers like Descartes, Hobbes, Spinoza and Locke, and tried to show that they were unreasonable and x No section is devoted to Stillingfleet in Charles de R~musat's Histoire de la Philosophie en Angleterre depuis Bacon jusqu'gt Locke, 2 vols. (Paris, 1875). He is of course briefly treated by Locke scholars, but only in relation to Locke. 2 Ernest C. Mossner, "Deism," Encyclopedia of Philosophy ('New York, 1967), II, 328. 3 Edward StiUingfleet,The Bishop o~ Worcester's Answer to Mr. Locke's Letter (London, 1697), pp. 37-38. [303] 304 HISTORY OF PHILOSOPHY destructive. Instead he advocated a commonsense philosophy incorporating Aristotelian and Stoic elements, as an adequate basis for a reasonable view of the world. Stillingflect's critique of empiricism, in its Epicurean and Lockean forms, revealed some of the basic difficulties in this emerging philosophy. His own views in some ways foreshadowed the counter-philosophy that Thomas Reid was to offer a century later against the full-blown empirical scepticism of Hume. And Hume's essay "Of Miracles" can, I believe, be seen as the reductio ad absurdum of Stillingfleet's commonsense philosophy. In this paper I shall try to sketch out Bishop Stilhngfleet's philosophy, and to indicate the role it played in the history of British empirical thought. The Bishop's attack on Locke only occurred at the very end of his long and fruitful intellectual career. (He died during the debate in 1699.) To appreciate why he was so concerned with exposing the sceptical and irreligious tendencies in Locke's thought, and the potential conflicts between empiricism and the tenets of Judeo-Christianity, one has to look at his entire theological and philosophical career. Stillingfleet was one of the most erudite divines of the seventeenth century, a leading member of the brilliant group of Anglican theologians, including, besides himself, William Chillingworth, Bishop John Wilkins (the founder of the Royal Society), and Archbishop John Tillotson.4 Stillingfleet was extremely sensitive to the fundamental issues being raised in the religious, scientific and philosophical debates of the time, and tried, like his fellow Anglican divines, to develop a commonsense semirational, semiempirical defense... (shrink)

It is shown that logical contradictions are derivable from natural translations into first order logic of the description and background assumptions of the Soros Game, and of other games and social contexts that exhibit conflict and reflexivity. The logical structure of these contexts is analysed using proof-theoretic and model-theoretic techniques of first order paraconsistent logic. It is shown that all the contradictions that arise contain the knowledge operator K. Thus, the contradictions do not refer purely to material objects, and do (...) not imply the existence of inconsistent, concrete, physical objects, or the inconsistency of direct sensory experience. However, the decision-making of rational self-interested agents is stymied by the appearance of such intensional contradictions. Replacing the rational self-interest axioms with axioms for an appropriate moral framework removes the inconsistencies. Rational moral choice in conflict-reflexive social contexts then becomes possible. (shrink)

1. The principal question I want to raise is that of the interpretation of what you call Parmenides' "wildly paradoxical conclusions about the impossibility of plurality and change." An argument that leads to a truly paradoxical conclusion is always open to construction as a reductio ad absurdum. And the biographical tradition represents Parmenides--quite unlike Heraclitus, for instance--as a reasonable and even practically effective man, not at all a fanatic. It therefore seems natural to ask, if he maintained a paradoxical (...) doctrine, whether it did not possess for him an interpretation that made some sense. Further, setting aside this not very weighty prima facie argument, I think the search for plausible interpretations is worthwhile in any case: for to make a rational assessment of the historical evidence one needs the widest possible survey of hypotheses to choose among; since conclusions in such matters are always uncertain, a list of possibilities may retain a kind of permanent value, as the best we can do; and readings which are even dismissed as unsound on adequate critical grounds may still be of interest, both for the understanding of historical influence--I have in mind in the present case especially Parmenides' influence on Plato--and for our own philosophical edification. (shrink)

Kimi zaman akademik hayatımızı doğrudan etkileyen kararların kimler tarafından nerede ve nasıl alındığını bilemeyebiliriz. Kimi zaman da bilsek bile bu akademik toplumun şeffaf olduğu anlamına gelmeyebilir. Doktora sonrası yurda dönmeden önce, tezimi okuyan hocalarımdan “Orada seni anlayan birilerini bulabilecek misin?” gibi bir soru gelmişti. Sorunun doğru yanıtının ne olduğundan emin değildim; hala da değilim.

The argument diagramming method developed by Monroe C. Beardsley in his (1950) book Practical Logic, which has since become the gold standard for diagramming arguments in informal logic, makes it possible to map the relation between premises and conclusions of a chain of reasoning in relatively complex ways. The method has since been adapted and developed in a number of directions by many contemporary informal logicians and argumentation theorists. It has proved useful in practical applications and especially pedagogically in teaching (...) basic logic and critical reasoning skills at all levels of scientific education. I propose in this essay to build on Beardsley diagramming techniques to refine and supplement their structural tools for visualizing logical relationships in a number of categories not originally accommodated by Beardsley diagramming, including circular reasoning, reductio ad absurdum arguments, and efforts to dispute and contradict arguments, with applications and analysis. (shrink)

Don Marquis’ future-like-ours account argues that abortion is seriously immoral because itdeprives the embryo or fetus of a valuable future much like our own. Marquis was mindful ofcontraception being reductio ad absurdum of his reasoning, and argued that prior tofertilisation, there is not an identifiable subject of harm. Contra Marquis, Tomer Chaffercontends that the ovum is a plausible subject of harm, and therefore contraception deprives theovum of a future-like-ours. In response, I argue that being an identifiable subject of harm (...) is notsufficient for Marquis’ argument to succeed. In addition, we must also share our identity withan ovum. I show that on the account of personal identity utilised by Marquis’ defenders, weare not identical with an ovum. As a result, Chaffer’s reductio fails. (shrink)

ABSTRACT William Hurlbut, a Stanford University bioethicist and member of the President's Council on Bioethics, recently proposed a solution to the current impasse over human embryonic stem cell research in the United States. He suggested that researchers could use genetic engineering and somatic cell nuclear transfer (i.e. cloning) to develop human ‘pseudo‐embryos’ that have no potential to develop fully into human persons. According to Hurlbut, even thinkers who typically ascribe high moral status to human embryos could approve of destroying these (...) ‘pseudo‐embryos’ for the sake of harvesting human embryonic stem cells. This essay argues, first, that an argument based on the ‘paradox of the heap’ (an argument that many ‘pro‐life’ thinkers employ in order to defend the notion that human embryos have high moral value from the moment of conception) challenges the ethical legitimacy of Hurlbut's proposal. Second, the paper argues that this conflict may illustrate a reductio ad absurdum for this ‘pro‐life’ argument itself rather than being a problem for Hurlbut's proposal. As a result, the paper challenges the ‘pro‐life’ strategy of arguing that one should respond to uncertainty about the moral status of developing embryos by being morally ‘cautious’ and granting all human embryos full moral status from the moment of conception. It appears that one is faced with a complex series of choices (about where to draw the moral line between entities that are human persons and entities that are not), and a strict moral ‘cautiousness’ about this series of choices may ultimately lead to absurdity. (shrink)