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 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)

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)

The general question to which Edwards here addresses himself is "whether any event whatsoever, and volition in particular, can come to pass without a cause of its existence," and among other arguments for a negative answer he has a reductio ad absurdum, arguing that if an act of will can occur without a cause, then anything at all, no matter how fantastic, can occur without a cause. There is, he says in effect, an inner contradiction in the notion (...) that uncaused events are bound always to be acts of will. We must note, however, in following his argument through, that his language is not quite that which I have just used, and in particular he does not speak primarily of what "occurs" but rather of what "begins to be." He says. (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.

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)

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)

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)

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.

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)

Can there be a good argument for the total denial of rule following? The question concerns the "total" denial, where the targeted rules include those meta-rules presumably required for philosophical argumentation. In this paper the author contends that such a self-undermining argument can never be a good argument even in a "reductio ad absurdum" form, but that the defender of rule following cannot dismiss a challenge on this ground when the opponent adopts "the virus strategy".

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)

In this paper, the role played in learning to argue by an essential and yet under-researched epistemic and argumentative norm is discussed, namely, the consistency requirement. An argumentative intervention is presented, that is designed to enhance the understanding of this norm among high school students, to enable them to recognize contradictions in the process of argumentation and to familiarize them with the argumentative strategies related to the reductio ad absurdum. There follows a description of how the designed intervention (...) was implemented in two Italian high schools, which served as an exploratory case study, and the results obtained are discussed. (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.

I show that what Quine calls 'pressing from above' is an argument for indeterminacy of translation that is generated by assuming the partial interpretation view of scientific theories. Furthermore, I argue that Quine's thesis should be understood as a reductio ad absurdum of partial interpretation and/or the view that the meaning of a term determines a unique extension for the term.

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.

Mencius, a prominent Confucian philosopher in the Warring States period of ancient China, is well-known for his argumentative skills, including his refutational skills used to maintain his own standpoints. This paper attempts to reveal how Mencius refuted his opponents argumentatively and strategically on the issue of human nature. To this end, the pragma-dialectical approach to argumentation is adopted to first reconstruct Mencius’s argumentative discourse on human nature according to the four stages in critical discussion—the confrontation, opening, argumentation and concluding stages. (...) Under the ancient Chinese historical and cultural context, Mencius’s argumentative discourse about human nature was developed in three critical discussions, between Mencius the protagonist, and his explicit interlocutors and implicit adversaries who held different views on human nature—the antagonists. The discussions were undertaken around three single mixed differences of opinion concerning three propositions, with resolution of the first difference of opinion serving as a starting point of the second, and the resolution of the second as a starting point of the third. Then based on the reconstruction, the paper elaborates the refutational strategies that Mencius employed in various stages, such as dissociation, reductio ad absurdum based on refutational analogy, and conciliation. It further points out that the employment of these strategies is strategic maneuvering undertaken by Mencius in an attempt to realize both dialectical and rhetorical aims. (shrink)

This paper is a response to Haze’s brief argument for the falsity of the theory that instantial terms refer arbitrarily, proposed by Breckenridge and Magidor in 2012. In this paper, I characterise instantial terms and outline the theory of arbitrary reference; then I reconstruct Haze’s argument and contend that it fails in its purpose. Haze’s argument is supposed to be a _reductio ad absurdum:_ according to Haze, it proves that a contradiction follows from the most basic tenets of the (...) theory of arbitrary reference. I will argue, however, that the contradiction in question follows not from these tenets, but from the surreptitious use that Haze makes of a self-referential expression. I conclude, consequently, that Haze’s argument is nothing more than an illustration of the well-known fact that self-referential expressions produce paradoxical results. (shrink)

Thomas Kuhn has argued that scientists never reject a paradigm without simultaneously accepting a new paradigm. Coupled with Kuhn's claim that it is paradigms as a whole, and not individual theories, that are accepted or rejected, this thesis is seen as one of Kuhn's main challenges to the rationality of science. I argue that Kuhn is mistaken in this claim; at least in some instances, science rejects a paradigm despite the absence of a successor. In particular, such a description best (...) fits Kuhn's most discussed example, the Copernican Revolution. By differentiating scientific discoveries into three types, spontaneous, implicit, and directed, we see that Kuhn's thesis holds for spontaneous and implicit discoveries, but not directed discoveries. Directed discoveries must be understood by an alternative account of falsifiability, based on argument by reductio ad absurdum rather than argument by modus tollens as traditional accounts of falsifiability would have it. (shrink)

The two extant versions of Gorgias’ Peri tou mē ontos have been preserved by an anonymous author and by Sextus Empiricus. Both versions have been differently interpreted by scholars who examine either the doctrine or the rhetorical-communicational dimen­sion. When comparing the PTMO with the rest of Gorgias’ works, the present paper aims to demonstrate that S.E. offers a more precise account of Gorgias’ modus argumentandi. Thus, S.E. shows the following, typical features of Gorgias’ demonstra­tive reasoning: 1) application of demonstrandum (...) and quod erat demon­strandum, 2) continuous employment of reductio ad absurdum and 3) a refined formulation of the principle of non-contradiction. The MXG, on the other hand, is accurate in the discussion of particular arguments, but presents an interpreter who is more interested in questioning Gorgias rather than doing justice to his thought. Hence, this article concludes that it was S.E., who had the text or at least a relatively accurate summa­ry of the PTMO. (shrink)

I. In “Whitehead’s Theory of Becoming," V.C. Chappell asserts that Whitehead’s “epochal theory of time or becoming is both untenable and unnecessary”. It is untenable, he argues, because “ … the theory itself is unintelligible, and … … the Zenonian argument on which the theory is founded, even in its amended, Whiteheadian version, is invalid”. Although it is not clear to me that Whitehead’s use of Zeno’s arguments is unsound, our concern here will be limited to the first of these (...) two claims. I will attempt to show that Chappell’s demonstration of the unintelligibility of Whitehead’s theory begs the question. His purpose is to present us with a reductio ad absurdum of the epochal theory of time, but he succeeds only in demonstrating that if we substitute other premises for Whitehead’s own, his conclusions will not be consistent with these substitute premises. (shrink)

We study how to postpone the application of the reductio ad absurdum rule (RAA) in classical natural deduction. This technique is connected with two normalization strategies for classical logic, due to Prawitz and Seldin, respectively. We introduce a variant of Seldin’s strategy for the postponement of RAA, which induces a negative translation from classical to intuitionistic and minimal logic. Through this translation, Glivenko’s theorem from classical to intuitionistic and minimal logic is proven.

Inferential or epistemic conditional sentences represent a blueprint of someone’s reasoning process from premise to conclusion. Declerck and Reed (2001) make a distinction between a direct and an indirect type. In the latter type the direction of reasoning goes backwards, from the blatant falsehood of the consequent to the falsehood of the antecedent. We first present a modal reinterpretation in terms of Argumentation Schemes of indirect inferential conditionals (IIC’s) in Declerck and Reed (2001). We furthermore argue for a distinction between (...) epistemic-modal strong and deontic-modal weak IIC’s. In addition, we extend the category of the indirect inferential conditionals in order to include several other deontic-modal subtypes. On the basis of the undesirability of the consequent the hearer in these cases infers that the antecedent is also undesirable. In this way the rhetoric-argumentative strategy of Reductio ad Absurdum is extended from the realm of deductive reasoning to that of practical reasoning. (shrink)

The article is a reductio ad absurdum of assumptions which are shared by a large number of followers of the animal welfare movement and utilitarianism. I argue that even if we accept the main ethical arguments for a negative moral assessment of eating meat we should not promote vegetarianism but rather beefism (eating only meat from beef cattle). I also argue that some forms of vegetarianism, i.e. ichtivegetarianism, can be much more morally worse than normal meat diet. In (...) order to justify these thesis I show that there are significant moral differences in the consumption of animal products from different species. (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)

This essay tries to show that there exist several passages where Kierkegaard (and his pseudonyms) sketches an argument for the existence of God and immortality that is remarkably similar to Kant's so-called moral argument for the existence of God and immortality. In particular, Kierkegaard appears to follow Kant's moral argument both when it comes to the form and content of the argument as well as some of its terminology. The essay concludes that several passages in Kierkegaard overlap significantly with Kant's (...) moral argument, although Kierkegaard ultimately favors revealed faith over natural theology in general and Kant's moral faith in particular. Whereas Kant uses the moral argument to postulate the existence of God and immortality, Kierkegaard mainly uses it as a reductio ad absurdum of non-religious thinking. (shrink)

After a chapter which is an introduction to and summary of the rest of the book, chapter 2 begins by criticizing various attempts to do away with theories, such as the Reichenbach-Salmon conception of theoretical truth in terms of observational consequences, and the Ramsey strategy of replacing first-order theoretical sentences by second-order nontheoretical ones; it then argues against hypothetico-deductivist theories of confirmation on the grounds that they are unable to handle the relevance of evidence to theory, whether or not (...) other formal constraints or even nonformal ones such as simplicity and explanatory power are added to those theories; it ends with an exposition of the Reichenbach-Carnap conventionalist thesis that the confirmation of hypotheses with evidence presupposes analytic principles connecting hypothetical and empirical concepts. Chapter 3 criticizes Bayesian theories of confirmation on such grounds as that the a priori arguments for Bayesian restrictions on beliefs are insufficient; that the Bayesian explanations of notions like variety of evidence, ad hocness, and simplicity are inadequate; and that they cannot account, without drastic revisions, for the relevance of evidence to theory, especially old evidence to new theory. Chapter 4 is an unsympathetic account of historically oriented philosophies of science; Lakatos’s notion of progressive research programs and Laudan’s theory of problem-solving effectiveness are found to be insufficiently precise and dubbed examples of "new fuzziness", while the Sneed-Stegmüller dynamics of theories is regarded as "a paradigm of misplaced rigor" ; and all three are criticized as unable to explicate the concept of evidential relevance. Chapter 5 is a formal and informal elaboration of the basic idea in Glymour’s account of theory and evidence, namely that confirmation or support is a three-term relation among evidence, hypothesis, and theory, so that evidence confirms an hypothesis only relative to a theory, and such that evidence e confirms hypothesis h relative to T if T with e implies, but T without e does not imply, an instance of h, and T with e does not imply a comparable hypothesis h’ different from h; the most interesting part of this chapter is a series of discussions showing how such an idea makes sense of the "methodological truisms" that it is possible selectively to test certain parts of a theory but not others, that a theory is supported better by a greater variety of evidence, that redundant or physically meaningless quantities are an undesirable feature of theories, that there are no inviolable rules, that a "white shoe" does not confirm "all ravens are black," that a theory is more useful and better supported than the set of its observational consequences, and that the hypothetico-deductive method often works. Since Glymour claims no originality for the conception of this general account, but only for its description, he plausibly thinks it necessary to apply it to some important historical cases of actual science; he does so in the next chapter by discussing at some length the structure and merits of Ptolemaic and Copernican astronomy, of Newton’s universal gravitation, of nineteenth century atomism, of Freud’s Rat Man, and of general relativity. For example, he argues convincingly that Copernicanism was better supported by the evidence available even before the telescope because it alone, and not the Ptolemaic theory, can determine some planetary properties which are presupposed by both theories, can test and confirm some common hypotheses, and can be confirmed in an essential rather than incidental manner; and though Glymour admits that the Copernicans tended to argue in terms of explanatory rather than confirmatory superiority, he sketches an interesting account of the relation between explanation and confirmation which strengthens his case. He also analyzes the text at the beginning of book 3 of Newton’s Principia and compiles a reconstruction of the intricate details of the inferential structure of the argument to universal gravitation; his impressive reconstruction clearly shows that Newton’s method is neither the inductivist one he himself thought he was following, nor the one attributed to him by Pierre Duhem, but rather one in accordance with Glymour’s so-called "bootstrap strategy" of repeatedly using the evidence from Kepler’s second and third laws, from lunar data, and from falling bodies, together with the theory consisting of the second and third laws of motion, to arrive at increasingly general instances of the principle of universal gravitation. Glymour’s account of arguments for and against the atomic theory from Thomson to Cannizzaro is his longest historical example, but he himself admits that this illustration of the bootstrap strategy is "certainly not the neatest", and rather "diffuse, and perhaps disconnected". Chapter 7 is a detailed application of the same principles to the technique known among social scientists as "causal modeling"; since such "causal models" are essentially systems of algebraic equations, Glymour’s account shows indirectly that the bootstrap strategy is applicable to any scientific theory presented as a set of algebraic equations; this, of course is not surprising, since the formal considerations with which Glymour begins the exposition of his theory in chapter 5 involve systems of algebraic equations. Chapter 8 is an attempt to apply Glymour’s theory of evidence to the very common scientific practice of curve-fitting, where one measures values of two or more quantities and then infers a functional relationship; Glymour argues that simpler polynomials are preferred because they are tested more frequently and more severely by the data and because they are more informative; but then he criticizes his own explanation and concludes that "the bootstrap procedures of chapter 5 do not seem to help the problem much more than a whit" ; this is admirably honest, but if one wants an additional logical or methodological rationale, then one would perhaps have to go to the meta-level and say that Glymour is here testing his own theory, and he is more interested in a further illustration of the bootstrap methodology even with a failed test, than he is to claim universal or exclusive validity for it. In chapter 9 Glymour uses his bootstrap theory of confirmation to criticize geometrical conventionalism; he considers the alternative theories of space or space-time proposed by conventionalists to show the radical undetermination of geometries by evidence, for example, a non-Euclidean geometry with no universal force instead of Newtonian gravitation with Euclidean geometry; he argues that such alternatives are simply not as well tested as the originals and that their equivalence to the originals is questionable. The last chapter is a brief discussion of further problems worthy of future investigation. (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)

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)

In lieu of an abstract, here is a brief excerpt of the content:Hume Studies Volume 29, Number 1, April 2003, pp. 29-41 Hume's Argument for the Temporal Priority of Causes TODD RYAN In a section entitled "Of Probability; and of the idea of cause and effect," Hume embarks on a search for the conceptual components of our idea of causation. Rejecting the possibility of analyzing the idea in terms of the qualities of objects, Hume claims to discover two constituent relations. (...) First, a cause and effect must be contiguous in space and time because "nothing can operate in a time or place, which is ever so little remov'd from those of its existence" (T 1.3.2.6; SBN 75).x Second, a cause must be temporally prior to its effect. Although experience is said to confirm this latter requirement "in most instances," Hume goes on to present an argument purporting to demonstrate that the temporal priority of a cause is an essential feature of every instance of causation.2 Despite the extensive treatment that his analysis of causation has occasioned, Hume's argument for the temporal priority of causes has received comparatively little attention. In this paper I hope to remedy this neglect by providing a more accurate explication of the argument than has previously been offered. Hume does not argue directly for the claim that a cause must be temporally prior to its effect. Rather he offers an alleged reductio ad absurdum of the opposing view that "'tis not absolutely necessary a cause shou'd precede its effect; but that any object or action, in the very first moment of its existence, may exert its productive quality, and give rise to another object or action, perfectly co-temporary with itself (T 1.3.2.7; SBN 76)." This careful summary Todd Ryan is Assistant Professor of Philosophy, Trinity College, Hartford, CT 06106-3100, USA. e-mail: [email protected] 30 Todd Ryan of the opposing view provides a clear statement of what Hume takes to be at issue, namely whether it is "absolutely necessary" that a cause be temporally prior to its effect. From this it can readily be inferred precisely what would count as a refutation of his own view. Specifically, if it could be shown that some objects can produce their effect perfectly contemporaneously with themselves, then his position would have to be abandoned.3 It is against this latter possibility that Hume directs his argument. He writes: 'Tis an establish'd maxim both in natural and moral philosophy, that an object, which exists for any time in its full perfection without producing another, is not its sole cause; but is assisted by some other principle, which pushes it from its state of inactivity, and makes it exert that energy, of which it was secretly possest. Now if any cause may be perfectly co-temporary with its effect, 'tis certain, according to this maxim, that they must all of them be so; since any one of them, which retards its operation for a single moment, exerts not itself at that very individual time, in which it might have operated; and therefore is no proper cause. The consequence of this wou'd be no less than the destruction of that succession of causes, which we observe in the world; and indeed, the utter annihilation of time. For if one cause were co-temporary with its effect, and this effect with its effect, and so on, 'tis plain there wou'd be no such thing as succession, and all objects must be co-existent (T 1.3.2.7; SBN 76). The general structure of the argument is reasonably clear. According to the "establish'd maxim" (hereafter EM) any object that does not produce an effect as soon as possible is not the "sole cause" of that effect. Assuming then that causes might occur simultaneously with their effects, it follows that every proper cause must be contemporaneous with its effect. But if every effect occurs simultaneously with its cause, then we arrive at the absurd conclusion that there can be no causal (or indeed temporal) succession in the world. Therefore, the original assumption that a cause may be perfectly co-temporary with its effect must be... (shrink)

‘Moral bioenhancement’ refers to the use of pharmaceuticals and other direct brain interventions to enhance ‘moral’ traits such as ‘empathy,’ and alter any ‘morally problematic’ dispositions, such as ‘aggression.’ This is believed to result in improved moral responses. In a recent paper, Tom Douglas considers whether medical interventions of this sort could be “provided as part of the criminal justice system’s response to the commission of crime, and for the purposes of facilitating rehabilitation : 101–122, 2014).” He suggests that they (...) could “at least in some cases, permissibly be provided without valid consent : 101–122, 2014)” as a form of rehabilitative punishment. He argues for this conclusion by ‘parity of reasoning,’ starting from the currently accepted practice of non-consensual incarceration. His argument appears to be dependent on the successful defence of the following two claims: that non-consensual incarceration is a morally justifiable practice, and that there is no meaningful distinction between the forcible imposition of this practice, and the forcible imposition of medical interventions on prisoners. From both claims, he deduces : if non-consensual incarceration is morally justifiable, so is the non-consensual imposition of medical correctives, in some cases. In this paper, I begin by suggesting that the basic argument behind the Parity Claim results in a reductio ad absurdum, whereby any practice that is sufficiently similar to incarceration in the ways Douglas presents, would also be considered permissible. This appears to be an unpalatable conclusion, casting doubt on the soundness of a key premise. Douglas appears to offer no means of deciding which practices are sufficiently similar to incarceration in terms of harm and threat to agency, and of the practices that I will present, which do seem to be, it does not seem that he could rule them out in any principled way. Next I turn to dispute claim relating to the purported justifiability of incarceration on rehabilitative grounds. If successful, this attack causes a break in reasoning from the justifiability of incarceration, to the justifiability of medical interventions. Medical interventions would then require an alternative, independent justification, through outlining the ways in which they are conducive to a particular aim of punishment, without relying on the justifiability of incarceration. This argument has not been provided, and I suggest that attempts to do so may run into difficulty. I untangle and make explicit the various assumptions made in Douglas’ contention that medical interventions “might be thought conducive to rehabilitation in some offenders,” locating my critique in the wider debate on the causes of crime. Finally, I seek to challenge the normative weight of the Parity Claim, arguing that to show that two practices are comparable in some sense is not sufficient to show that both are equally as permissible. Other social purposes must be considered, leading me to suggest that the forcible imposition medical correctives falls beyond the appropriate remit of the criminal justice system. (shrink)

In this dissertation I examine the sceptical problem of rule following presented by Saul Kripke in his interpretation of Ludwig Wittgenstein's later works: Do any facts determine what rule we were following in our apparently rule-following activities such as the use of language? I distinguish three ways of understanding this question--modest scepticism, radical scepticism, and metascepticism--and address them in Parts 1, 2 and 3 of the dissertation, respectively. ;Part 1 discusses modest scepticism, which asserts that no finite (...) facts about humans can determine rules which have infinitely many possible applications. I resolve this apparent conflict between the finite and the infinite by incorporating the recursiveness of rule applications into the theory of rules. ;Part 2 discusses radical scepticism, which asserts that no facts determine what normative rules we were following. I show first that this challenge has a wider scope than the Humean Thesis of the underivability of ought from is, and that as a result, the radical sceptic can refute attitudinal theories of norms, which have been considered a possible response to the Humean challenge. I then propose a solution to radical scepticism which explains our practice and beliefs about normative rules without assuming the existence of rule-determining facts. Unlike the solution Kripke ascribes to Wittgenstein, it offers no justification of our practice and beliefs about normative rules. Some methodological implications of the solution are also explored. ;Part 3 discusses metascepticism about rule following, whose challenge extends to the rules used for the very discussion of rule following. I examine first whether such a challenge is self-undermining in that it makes the sceptical argument itself impossible. I propose an extended form of reductio ad absurdum argument by which the metasceptic can challenge rules in general, including those used in the sceptical argument. Then I argue that the solution to radical scepticism given in Part 2 survives metascepticism as well. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Philosophy 41.1 (2003) 121-122 [Access article in PDF] Harold Tarrant. Plato's First Interpreters. Ithaca, NY: Cornell University Press, 2000. Pp. viii + 263. Cloth, $55.00. This is Tarrant's third book on the ancient Platonist tradition, following his Scepticism or Platonism? (1985) and Thrasyllan Platonism (1993). In those earlier volumes his focus was on the first centuries bc and ad. Here his scope is (...) much wider. Stating that "Platonic interpretation is today at a crossroads," he has written a book that explores "ancient attempts to wrestle with this corpus," with the ultimate objective "to encourage a fresh, almost primitive reading of Plato himself" (vii).He begins engagingly by confronting the ancients with questions any modern reader of Plato must ask: What kind of text is this? Are there doctrines here? Where do I look for Plato's doctrines? The second part of his book is a historical survey, taking us from Plato, the early Academy and Aristotle, through the Hellenistic and early Roman Imperial period, and concluding with the principal Neoplatonist interpreters. In the third and longest part, he focuses on the interpretation of specific dialogues, giving most space to the Gorgias and Theaetetus, but also dealing in particular detail with the Meno, Parmenides, and Philebus. Something is said about every dialogue, but Tarrant writes only briefly about such major works as the Republic and Timaeus. He explains his selectivity (not very convincingly) as due to his wish to "discuss issues of meta-interpretation, with emphasis on the period before Plotinus" (198).Taking his book as a whole, one realizes that few strands of modern interpretation were not prefigured to quite a large extent in antiquity. The two most obvious exceptions are the chronological and developmental approach (Early, Middle, and Late), at present under strong attack from some quarters, and the theological, numerological, and allegorical readings practiced by Neoplatonists. Plato's ancient interpreters were doctrinal unitarians, but they implicitly anticipated our tendency to distinguish "Socratic dialogues," which some of them called "gymnastic" and "inquisitive," from such "canonical" works as the Phaedo,Republic, Symposium, and Timaeus, to which they applied the labels "dogmatic" and "expository." And they recognized that both types of characteristics could be found in the same dialogue, as in the Meno and Theaetetus. Plato himself, they proposed, spoke primarily through the voices of Socrates, Timaeus, and the Eleatic and Athenian strangers; but other characters, such as Pausanias in the Symposium, or Protagoras in the dialogue of that name, utter thoughts with some philosophical value. In explaining difficult passages of one dialogue, they would typically refer to passages from other parts of the corpus. An especially intriguing instance is the strategy of the Anonymous Commentator on the Theaetetus, who reads the Meno into the dialogue on which he is officially commenting.Ancient scholars, just like ourselves, asked questions about the unifying themes of complex dialogues. Hence the sub-titles given to certain works: "On the soul" for the Phaedo, and "On justice" for the Republic, etc. For Olympiodorus (whose commentary on the Gorgias Tarrant has recently co-edited [Leiden, 1998]), earlier interpreters have seriously erred by giving too limited an account of that dialogue's scope. It is not, he says, simply about rhetoric, nor about justice and injustice; nor is its theme the divine demiurge (as some Neoplatonists had strangely proposed, on the basis of the concluding myth). Rather, the subject of the Gorgias is "the ethical principles that lead to constitutional well-being" (125). [End Page 121] However, Olympiodorus's eminently "sensible" reading (as Tarrant calls it) is deeply embedded in the Neoplatonic contrast between the "purificatory virtues" of the Phaedo and the "constitutional virtues" of Republic4.Strong or weak scepticism, esotericism, unwritten doctrines, spurious versus genuine, a canon of central dialogues, dramatic considerations, and the philosophical importance or non-importance of the dialogues' prologues—all of these are interpretive approaches that Tarrant surveys in this immensely learned book, and all of them continue to resonate for us. Modern scholars, who emphasize the literary and philosophical unity of each dialogue, are walking... (shrink)

Many interpreters have noted that §§138–242 of Wittgenstein's Philosophical Investigations is dominated by an attack on a platonist or classical realist conception of rules and meaning. In this paper, I address the lack of clarity that still exists concerning the nature and strength of the arguments in those sections. I argue that Wittgenstein's attack is genuinely compelling if viewed as an intricate reductio ad absurdum argument that runs all the way through §§138–201. On my reading, the well-known regress-of-interpretations (...) argument is merely one stage in the overall reductio and is not sufficient on its own to generate the rule-following paradox. (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.

Many interpreters have noted that §§138–242 of Wittgenstein's Philosophical Investigations is dominated by an attack on a platonist or classical realist conception of rules and meaning. In this paper, I address the lack of clarity that still exists concerning the nature and strength of the arguments in those sections. I argue that Wittgenstein's attack is genuinely compelling if viewed as an intricate reductio ad absurdum argument that runs all the way through §§138–201. On my reading, the well-known regress-of-interpretations (...) argument is merely one stage in the overall reductio and is not sufficient on its own to generate the rule-following paradox. (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)

Desmond Clarke's remarks on “my” absurdity argument are puzzling. i) Although I do indeed still believe it to be a valid argument, I certainly would not claim credit for it. I believe that “Reducibility: Another Side Issue?” put the general problem of the reducibility of mind into a somewhat unorthodox context, but the particular claim Clarke is attacking forms only one very unoriginal step in the general argument of that essay. ii) Some points that Clarke makes I would certainly agree (...) to, and believe I have agreed to in some of the texts he cites, while others are far from anything I meant to convey. Under Clarke's, 1) of course the “antinomies” of the paper above referred to trade on ambiguities. That's one of the points of the paper. 2) in both “Reducibility … ” and “To Have A Mind …”, I have tried to specify the sense in which “mechanism” was being used. That I do not take such terms as self-explanatory should be clear, for instance, from the remarks in the latter paper that immediately follow the passage Clarke criticizes. 3) I have no idea how physics is to develop in the future, nor did I wish to suggest that I did. With the rest of Clarke's I entirely agree. As to his, I fail to see its relevance to my argument, unless it simply leads up to and, with which, again, I wholeheartedly concur. Nancy Maull's paper, which Clarke refers to, for example, seems to me to shed great light on what used to be thought the problem of reduction; I don't see how her argument conflicts with “mine.” iii) Clarke's two “interpretations” of “my” argument are even more puzzling. The first paragraph is clear, as far as it goes. But the second is entirely murky. Perhaps I may try to reconstruct it. “The question for the scientist of a reductivist disposition in this context,” Clarke writes, “is: would it be possible to construct an alternative theory which adequately explains the same phenomena as the human sciences?” Fair enough. But apparently one is not allowed to reflect about an answer to this question. One has to wait and see if such a theory does develop. And meantime to notice that any theory by its very nature is intentional: this is to use some part of the human sciences to establish the explanatory power of all the human sciences. Is that what is meant? If so, I would reply: that the claim that theories are inherently intentional is not a thesis of any “human science” but a philosophical thesis about the nature of intelligible discourse. If a wholly non-intentional theory of human action were stated it would invalidate itself as theory. Thus, to respond to the major accusation of, we would have an answer to Clarke's question such that the question could not have been asked. What we have, then, is not a petitio but a valid reductio ad absurdum. (shrink)

This paper attempts to explicate the philosophical and theological premisses involved in Fr. Paneloux’s second sermon in Camus’ The Plague. In that sermon Fr. Paneloux says that the suffering of children is our bread of affliction. The article shows where one must start in order to get to that point, and what follows from it. Whether or not the argument given should be called a theodicy or a reductio ad absurdum of religious belief is an open question for (...) a philosopher, but the argument is shown to cohere with the traditional belief in God’s omnipotent goodness. (shrink)

With characteristic candour, David Hume is prepared to admit that in ordinary life, but certainly not when reflecting on the nature of perceptual experience, he has no option but to ‘believe in the existence of body’ despite his philosophical reasonings to the contrary. In this instance, his commitment to ‘Common Sense’ has become, as it was not to become for his contemporary Thomas Reid, a direct consequence of participating in a day-to-day existence if nevertheless one which he has no option (...) but to reject when reflecting in the study.Ludwig Wittgenstein, on the other hand, presents us with a picture of what has come to be regarded as a form of Humean ‘phenomenalist language’, private in nature, which, in one of the most famous passages of his later philosophy, he appears to reject via a form of reductio ad absurdum argument. In what follows, it will be questioned whether his ‘argument’ clearly represents phenomenalist proposals which Hume’s successors, e. g., A.J. Ayer, accepted without question. If there is a misunderstanding here on both sides, an investigation into its nature must lead to an appreciation of the varying roles attributed by these philosophers to the notion of ‘Common Sense’. (shrink)

There is a striking parallel between w v o quine's 'indeterminacy of translation' thesis and k o apel's 'indeterminacy of textual interpretation thesis. both arguments are based on what is essentially the same 'sceptical dilemma'. the key to resolving these 'hermeneutic problems' is to recognize that such a 'sceptical problem' is unintelligible. this is precisely the point of wittgenstein's discussions of rule-following. many have misunderstood this, however, for they have misconstrued what was intended to be read as a " (...) class='Hi'>reductio ad absurdum" establishing the "unintelligibility" of the dilemma, as a sceptical attack on the possibility of our ever solving the problem. (shrink)