This paper investigates in how far a theory of dialectical structures sheds new light on the old problem of giving a satisfying account of the fallacy of petitio principii, or begging the question. It defends that (i) circular argumentation on the one hand and petitio principii on the other hand are two distinct features of complex argumentation, and that (ii) it is impossible to make general statements about the defectiveness of an argumentation that exhibits these features. (...) Such an argumentation, in contrast, has to be evaluated on a case-by-case basis. “Petitio principii”, this paper thence suggests, is one name for, in fact, a multitude of different and quite complex dialectical situations which require specific analysis and evaluation. (shrink)

One of the most common strategies in philosophical dispute is that of accusing the opponent of begging the question, that is, of assuming or presupposing what is to be proved. Thus, it happens quite often that the credibility of a philosophical argument is infected by the suspicion of begging the question. In many cases it is an open question whether the suspicion is grounded, and the answer lurks somewhere in the dark of what the proponent of the argument does not (...) say. This is why it may take years, or even centuries, before the begging of the question is brought to light. But few philosophers would deny that once it is established that a certain argument begs the question, that argument has to be rejected without hesitation: question-begging arguments are bad arguments, hence one should not appeal to them. Logicians traditionally classify begging the question as a fallacy, that is, as a bad reasoning that seems good at first sight. The fallacy is known under the name of petitio principii. This paper originated in our dissatisfaction with definitions of petitio principii found here and there in logic textbooks. Although it is uncontroversial that there is something wrong with begging the question, it is not clear from those definitions what is wrong. (shrink)

In this paper I develop an account of petitio principii (the fallacy sometimes also called ‘vicious circularity’, or ‘begging the question’) which has two crucial features: it employs the notion of doxastic justification, and it takes circularity to be relative to an evidential state. According to my account, an argument will be circular relative to an evidential state if and only if having doxastic justification for the conclusion is necessary, for a subject in that evidential state, to have (...) doxastic justification for the premisses. I compare the account to some existing ones, and claim some advantages. I then rebut an objection which threatens to undermine the importance of one of those advantages. This account seems to shed new light on the old problem of characterizing petitio principii. It avoids the two obvious problems which any account of this phenomenon must face: being too narrow, for example by leaving out all arguments in which the conclusion does not appear among the premisses, and being too wide, making all valid arguments circular. (shrink)

It is a common complaint that the syllogism commits a petitio principii. This is discussed extensively by John Stuart Mill in ‘A System of Logic’ [1882. Eighth Edition, New York: Harper and Brothers] but is much older, being reported in Sextus Empiricus in chapter 17 of the ‘Outlines of Pyrrhonism’ [1933. in R. G. Bury, Works, London and New York: Loeb Classical Library]. Current wisdom has it that Mill gives an account of the syllogism that avoids being a (...) petitio by virtue of construing the universal premise as an inference-rule. I will show that both the problem and the role of inference-rules in its solution have been misunderstood. Inference-rules have very little to do with this problem, and I will argue further that nothing is gained with regard to this problem by the introduction of inference-rules in preference to premises. (shrink)

L’hypothèse d’un trompeur suppose la validité du critère des idées claires et distinctes. Le doute vient de ce que notre créateur peut nous avoir faits tels que, quelque soin que nous prenions d’atteindre des idées claires et distinctes, ce qui nous semble clair puisse ne pas l’être. Ce doute est fondé sur l’ignorance de la nature de notre créateur, et on peut y échapper, en appliquant le critère à la question : « Notre créateur peut-il nous tromper? » Bien que (...) le doute ne puisse être que rétrospectif, il n’a rien à voir avec l’exactitude de la mémoire. (shrink)

Abstract Few theoretical insights have emerged from the extensive literature discussions of petitio principii argument. In particular, the pattern of petitio analysis has largely been one of movement between the two sides of a dichotomy, that of form and content. In this paper, I trace the basis of this dichotomy to a dualist conception of mind and world. I argue for the rejection of the form/content dichotomy on the ground that its dualist presuppositions generate a reductionist analysis (...) of certain concepts which are central to the analysis of petitio argument. I contend, for example, that no syntactic relation can assimilate within its analysis the essentially holistic nature of a notion like justification. In this regard, I expound a form of dialectical criticism which has been frequently employed in the philosophical arguments of Hilary Putnam. Here the focus of analysis is upon the way in which the proponent of a position proceeds to explain or argue for his/her own particular theses. My conclusion points to the use of such dialectic within future analyses of petitio principii. (shrink)

If one looks to the current textbook lore for reliable taxonomic and analytical information about the petitio principii, one is met with conceptual disarray and much too much nonsense. The present writers have recently attempted to furnish the beginnings of a theoretical reconstruction of this fallacy which is at once faithful to its formidable complexity yet useful as guide for its detection and avoidance. The fact is that the petitio has had a lengthy and interesting history, and (...) in this paper we shall want to explore certain features of its development, such as it may have been. The principal origins of the concept of circular argument are to be found in Aristotle. The Aristotelian doctrine recurs with variations in the sophismata literature of the middle ages and in logic texts and manuals right up to the present day. (shrink)

Being needs a rectification, that is the compensation of being for Being, which was only assumed, but not substantiated by reason of the influence of the logical fallacy petitio principii and due to the loss of the absolute status of the verb to be from the Greek times to Heidegger's project of ontology. The annulment of the Greek status of the verb to be caused an absolute disorientation of being regarding its own object and method of action, which (...) ultimately led to the indifference of the ontological background as such. As a result, being did not turn into the smallest semantic unit, like the active parts of speech, but its semantic content expanded to infinity in an eclectic manner, and therefore, being eventually lost the autonomy and limits of its own phenomenological manifestation. This article, which is a part of a larger study at the same time, is based on the idea that negativity is presented as an original characteristic of being in the very first of the judgments about being, namely being is. It turns out that being exists, but only within the utterance, while it is not directly presented, what means it is deprived with predicative features peculiar to it exclusively, except for such one: being is/exists (but) not (only) as something or being is not (only) as something. The aim of the article is to define the negative copula of being as the subject of Heidegger's project of radical ontology, only sketched in the Marburg lectures of 1927. Besides, the current revival of scientific interest in the direction of subjectivity and spatial localizations of Nothing requires the confirmation of its being-nature, that logically follows from acquisition of the negativity-feature by being-copula, and then –the interpreting of negation as a solely ontological mode of action among the perspectives of the transition to a new beginning, which occupied all scientific research of Heidegger’s later thought. In view of the above, the relevance of copula-studies is only increasing. (shrink)

Traditionally, logicians construed fallacies as mistakes in inference, as things that looked like good (i.e., deductively valid) arguments but were not. Two fallacies stood out like a sore thumb on this view of fallacies: the fallacy of many questions (because it does not even look like a good argument, or any kind of argument) and the fallacy of petitio principii (because it looks like and is a good argument). The latter is the concern of this paper. One possible (...) response is to say that the tradition is right about the concept of fallacy but wrong about its extension: petitio principii is not a fallacy. If the only proper ways to criticize an argument are to say that it is invalid or that it is unsound, and petitio principii is not criticisable on either of these counts, then calling it a fallacy is tantamount to saying we should prefer invalid or unsound arguments Robinson (Analysis, 31(4): 114 ,1971). I will present a third way to logically criticize arguments and show that fallacious instances of petitio principii are so criticisable while other instances of petitio principii are non-fallacious; hence, this fallacy is not a reductio of the Standard Treatment. It is not my intention in this paper to come out on the side of any of the competing theories—the Standard Treatment, the dialectical theories, and the epistemic theories—as general theories of fallacy. I show only that petitio principii can be handled by something closely resembling the Standard Treatment in so far as that, on entirely logistical principles, there can be made a distinction such that circular arguments form at best a degenerate kind of argument. Circular arguments look like good arguments but are not, not because they are deductively invalid (which they are not) but because they do not deserve to be called arguments at all. (shrink)

Several of the so-called “fallacies” in Aristotle are not in fact mistaken inference-types, but mistakes or breaches of rules in the questioning games which were practiced in the Academy and in the Lyceum. Hence the entire Aristotelian theory of “fallacies” ought to be studied by reference to the author's interrogative model of inquiry, based on his theory of questions and answers, rather than as a part of the theory of inference. Most of the “fallacies” mentioned by Aristotle can in fact (...) be diagnosed by means of the interrogative model, including petitio principii, multiple questions, “babbling’, etc., and so can Aristotle's alleged anticipation of the fallacy of argumentum ad hominem. The entire Aristotelian conception of inquiry is an interrogative one. Deductive conclusions caught Aristotle's attention in the form of answers that every rational interlocutor must give, assuming only his own earlier answers. Several features of Aristotle's methodology can be understood by means of the interrogative model, including the role of endoxa in it. Theoretically, there is also considerable leeway as to whether “fallacies” are conceived of as mistakes in questioning or as breaches of the rules that govern questioning games. (shrink)

The article analyses the meta- epistemological problem of the justification of a theory of knowledge. The first section is dedicated to the morphological reconstruction of the problem, the second presents a diagnosis of the problem in terms of a metatheoretical and logically non- contradictory "petitio principii" and the third delineates the limits within which strategies for the treatment of the problem could be elaborated.

In recent and not so recent years, fallacy theory has sustained numerous challenges, challenges which have seen the theory charged with lack of systematicity as well as failure to deliver significant insights into its subject matter. In the following discussion, I argue that these criticisms are subordinate to a more fundamental criticism of fallacy theory, a criticism pertaining to the lack of intelligibility of this theory. The charge of unintelligibility against fallacy theory derives from a similar charge against philosophical theories (...) of truth and rationality developed by Hilary Putnam. I examine how Putnam develops this charge in the case of the conception of rationality pursued by logical positivism. Following that examination, I demonstrate the significance of this charge for how we proceed routinely to analyse one informal fallacy, the fallacy of petitio principii. Specifically, I argue that the significance of this charge lies in its issuance of a rejection of the urge to theorise in fallacy inquiry in general and petitio inquiry in particular. My conclusion takes the form of guidelines for the post-theoretical pursuit of fallacy inquiry. (shrink)

Since its inception in the work on fallacies of Charles Hamblin, formal dialectic has been the object of an unparalleled level of optimism concerning the potential of its analytical contribution to fallacy inquiry. This optimism has taken the form of a rapid proliferation of formal dialectical studies of arguments in general and fallacious arguments in particular under the auspices of theorists such as Jim Mackenzie and John Woods and Douglas Walton, to name but a few. Notwithstanding the interest in, and (...) the hopes for, a formal dialectical analysis of the fallacies, such an analysis, I will demonstrate subsequently, leads to much unintelligibility in fallacy inquiry. The context of my argument will be the philosophical views of Hilary Putnam, particularly Putnam's claim that when we theorise in relation to rationality, the unintelligibility of the conception of rationality to emerge from this theoretical process can be traced to the circumscription of rationality within this theoretical process. I charge formal dialectic with effecting a similar circumscription of argumentative rationality, a circumscription that, I will claim, is generative of unintelligibility in formal dialectical analyses of the fallacies. In this case, the context for my claims will be the formal dialectical analyses of Walton and Batten, Rescher, Hamblin, Mackenzie and Hintikka, primarily in relation to the petitio principii fallacy. My conclusion examines a number of the reasons, both historical and conceptual, which have made it seem that it is possible to fully circumscribe the notion of argumentative rationality. (shrink)

We examine in detail three classic reasoning fallacies, that is, supposedly ``incorrect'' forms of argument. These are the so-called argumentam ad ignorantiam, the circular argument or petitio principii, and the slippery slope argument. In each case, the argument type is shown to match structurally arguments which are widely accepted. This suggests that it is not the form of the arguments as such that is problematic but rather something about the content of those examples with which they are typically (...) justified. This leads to a Bayesian reanalysis of these classic argument forms and a reformulation of the conditions under which they do or do not constitute legitimate forms of argumentation. (shrink)

In his article Evgeny Borisov offers an original solution to Kripke’s sceptical problem of meaning. Its conceptual core is the point of view of the participant of speech acts. He believes that first-person statements of speech act participants like “I know for certain that the expression ‘e’ is used by me in the meaning of m” cannot carry any epistemic fallacies. As a criticism, I propose to point out that non-factual Cartesian semantics have serious epistemic flaws that make it vulnerable (...) to sceptical attacks and accusations of petitio principii. (shrink)

My argument is that Chalmers’ Zombie fiction and his rigid-designator-argument going back on Kripke seems to come down to a petitio principii. Rather, at the core it appears to be more related to the essential ‘privacy’ of the phenomenal internal perspective. In return for Chalmers I argue that the ‘principle of self-preservation’ of living organisms necessarily implies subjectivity and the emergence of meaning. The comparison with a robot proves instructive. The mode of ‘mere physical’ being is transcended if, (...) in the form of phenomenal perception, meaning appears on the stage of higher animals – a transition explained here as an emergence phenomenon based on the systemic co-operation of perception, evaluation and action (‘percept-eval-act-system’). Some fundamental considerations are added: Those consequences implied by the principle of self-preservation reveal the natural-biological origin of the organism – primarily seeming a more insignificant circumstance – as a momentous fundamental difference (end-in-itself-character, subjectivity, constitution of meaning) compared to technical artefacts (robot). And the emergentist approach indicates the – maybe paradoxical – possibility of a dualism of physical and psychical phenomena in an overall physical system, that is not dualistic at the same time. (shrink)

Memory is ordinarily taken to be one of the most fundamental sources of knowledge. However, memory sceptics argue that memory is unable to provide us with knowledge about the past. In the existing literature, there are two most discussed forms of memory sceptical arguments, namely, the argument from memory reliability and the argument from underdetermination. Correspondingly, the two most representative anti-sceptical proposals nowadays attempt to disarm the two sceptical arguments by employing explanationism and disjunctivism respectively. This paper will first illustrate (...) their defects: The explanationist response fails to explain why the common-sense explanation is preferable. Besides, it succumbs to the petitio principii fallacy. The disjunctivist response fails to establish that memorial experiences are factive in paradigmatic cases. After that, a novel solution will be proposed, according to which memory sceptical arguments are self-hollowing, viz, their conclusions deprive their premises of the foundation of plausibility. (shrink)

This paper presents an analysis of the concept of burden of proof in argument. Relationship of burden of proof to three traditional informal fallacies is considered: (i) argumentum ad hominem, (ii) petitio principii, and (iii) argumentum ad ignorantiam. Other topics discussed include persuasive dialoque, pragmatic reasoning, legal burden of proof, plausible reasoning in regulated disputes, rules of dialogue, and the value of reasoned dialogue.

The concept of burden of proof is used in a wide range of discourses, from philosophy to law, science, skepticism, and even in everyday reasoning. This paper provides an analysis of the proper deployment of burden of proof, focusing in particular on skeptical discussions of pseudoscience and the paranormal, where burden of proof assignments are most poignant and relatively clear-cut. We argue that burden of proof is often misapplied or used as a mere rhetorical gambit, with little appreciation of the (...) underlying principles. The paper elaborates on an important distinction between evidential and prudential varieties of burdens of proof, which is cashed out in terms of Bayesian probabilities and error management theory. Finally, we explore the relationship between burden of proof and several (alleged) informal logical fallacies. This allows us to get a firmer grip on the concept and its applications in different domains, and also to clear up some confusions with regard to when exactly some fallacies (ad hominem, ad ignorantiam, and petitio principii) may or may not occur. (shrink)

One crucial part of the Aristotle´s discussion of the principle of non-contradiction in Metaphysics IV 4 is his notion of semainein hen, which must be carefully distinguished from the closely connected notion of semainein kath´ henos. The Aristotelian proof is located at 1006b28-34 and it is argued that it does not suppose any bit of essentialism nor does it contain any petitio principii; some improvements are further proposed to the current translations.

Defenses of realist reductionism may involve petitio principii by a tacit and inadvertent reintroduction of naïve realism through continued supposition of stimulus and sensory fields' conflation. The legitimate meaningfulness of identity statements involving scientific discoveries is examined, as are their illicit or gratuitous expressions. While experimental psychological data has a role to play in refutation of direct realism, we should not underestimate the ingenuity of its proponents' extenuations , hence the need for emphasizing the logic of perceptual processes (...) for conclusive refutation of philosophic realism. A further instance of Paul Churchland's misinterpretation of psychophysical correspondence as intertheoretic identification is given, concerning Edwin Land's retinex theory of color vision. (shrink)

Eternal recurrence and the principle of economy in Nietzscheʼs thought. This paper explores the place that the principle of parsimony occupies in Nietzscheʼs thought. I argue that the principle of parsimony is one of the criteria that allow Nietzsche to organize the many different interpretations available to us into a hierarchy. The question is whether Nietzsche can justify the use of this principle without making it a petitio principii. Oddly enough, it seems that eternal recurrence has a role (...) to play in this context. The most important problem Nietzsche has to confront is the problem of circularity. Bringing together Nietzsche’s specific conception of truth with the problem of eternal recurrence allows us to recognize that circularity provides for access to a higher density of the real. (shrink)

Deleuze’s philosophy of painting can be seen to pose certain challenges to a phenomenological approach to philosophy. While a phenomenological response to Deleuze’s philosophy is clearly needed, I show in this article how an approach taken in a recent paper by Christian Lotz proves inadequate. Lotz argues that through Deleuze’s refusal to accept the place of representation in art, he is unable to distinguish art from decoration, or to give a coherent account of how the content of art can be (...) represented. I show that this criticism emerges from a misreading of the place of representation in Deleuze’s philosophy. I will argue that by failing to take account of some of the key features of Deleuze’s wider ontology, such as the importance of both the virtual and the actual for his analysis of objects, Lotz’s critique proves unsuccessful. In particular, I want to show that Lotz’s criticisms rest on a failure to attend to the systematic nature of Deleuze’s philosophy, and in particular, the place of Deleuze’s analysis of Bacon within the system as a whole. I will further show that Lotz’s phenomenological defence commits the fallacy of petitio principii, assuming the validity of the phenomenological method in order to justify the phenomenological approach. (shrink)

. Remarkably, despite the tremendous success of axiomatic set-theory in mathematics, logic and meta-mathematics, e.g., model-theory, two philosophical worries about axiomatic set-theory as the adequate catch of the set-concept keep haunting it. Having dealt with one worry in a previous paper in this journal, we now fulfil a promise made there, namely to deal with the second worry. The second worry is the Skolem Paradox and its ensuing Skolemite skepticism. We present a comparatively novel and simple analysis of the argument (...) of the Skolemite skeptic, which will reveal a general assumption concerning the meaning of the set-concept (we call it Connexion M). We argue that the Skolemite skeptics argument is a petitio principii and that consequently we find ourselves in a dialectical situation of stalemate.Few (if any) working set-theoreticians feel a tension – let alone see a paradox – between, on the one hand, what the Löwenheim–Skolem theorems and related results seem to be telling us about the set-concept, and, on the other hand, their uncompromising and successful use of the set-concept and their continuing enthusiasm about it, in other words: their lack of skepticism about the set-concept. Further, most (if not all) working settheoreticians have a relaxed attitude towards the ubiquitous undecidability phenomenon in set-theory, rather than a worrying one. We argue these are genuine philosophical problems about the practice of set-theory. We propound solutions, which crucially involve a renunciation of Connexion M. This breaks the dialectical situation of stalemate against the Skolemite skeptic. (shrink)

The paper analyses the argument proposed by Milne against truthmaker maximalism and shows that the objections raised to this argument by de Sa and Zardini, and Rodriguez-Pereyra are misguided because the first one misuses the vagueness of some terms; and the second one is based on a fallacy of petitio principii.

En el presente trabajo discuto la consistencia que elargumento de la inferencia a la mejor explicación ofrece al realismo, en particularal realismo científico. Mi trabajo está dividido endos partes. En la primera, trataré de explicar lasvirtudes del realismo, relacionándolo con la IME.En otras palabras, expondré los argumentos de porqué la IME es importante para el realismo científico.Adicionalmente mencionaré algunas definicionessobre teorías de la verdad para justificar cuál deellas es la más afín al realismo en general; y mereferiré a las diferencias (...) que existen sobre losdistintos niveles de realismo para mostrar que,por lo menos, uno de ellos puede ser compatiblecon una postura antirrealista, que en últimas esla que voy a defender. En la segunda, mostrarétres réplicas que se le pueden hacer a la IME si lointerpretamos como un razonamiento distintivodel realismo científico. El primer reparo es que losrealistas científicos incurren en un error categorialcuando hablan de términos observacionales yentidades teóricas; el segundo es que la IMEconstituye una petición de principio, siempre ycuando se use como un argumento realista; y latercera objeción consiste en mostrar que la IMEno es genuinamente un argumento exclusivo delrealismo científico ya que puede ser compatible conposturas empiristas o instrumentalistas.In this paper I try to discuss the consistencyargument that the inference to the best explanation offers to realism, in particular toscientific realism. My paper will be divided in twoparts. In the first one, I try to explain the virtuesof realism, relating it to IBE. In other words, I willdiscuss the arguments of why IBE is important forscientific realism. I also mention some definitionson theories of truth to justify which one is moreakin to realism in general. In addition, I will focuson the differences of various levels of realism toshow that, at least one of them may be compatiblewith an anti-realist position, which ultimately iswhat I defend. In the second part, I offer threereplies that can be given to IBE if we interpret it asan argument typical of scientific realism. The firstobjection is that scientific realists make a categorymistake when they talk about observation termsand theoretical entities, the second is that IBE turnsout to be a petitio principii, provided it is realisticto use it as an argument, and the third objection isthat IBE is not genuinely an argument exclusive ofscientific realism, since it may also be compatiblewith empiricist or instrumentalist views. (shrink)

We argue that thinking of the man-machine comparison in terms of a contest involves, in a reasonable scenario, a criterion of success that is neutral. This is because we want to avoid a petitio principii. We submit, however, that, by looking at things this way, one makes the most essential human things invisible. Thus, in a sense, the contest approach is self-defeating.

This article articulates and defends F. H. Bradley's regress argument against external relations using contemporary analytic techniques and conceptuality. Bradley's argument is usually quickly dismissed as if it were beneath serious consideration. But I shall maintain that Bradley's argument, suitably reconstructed, is a powerful argument, plausibly premised, and free of such obvious fallacies as petitio principii. Thus it does not rest on the question‐begging assumption that all relations are internal, as Russell, and more recently van Inwagen, maintain. Bradley (...) does not attack external relations in order to affirm a doctrine of internal relations, and his monism is not derived from the internality of all relations, but from the self‐contradictory nature of all relations. For Bradley, it is the “relational situation”as such that is ontologically defective. (shrink)

Kim’s Ontological Physicalism (OP) presents itself as a naturalistic and monistic metaphysical framework, aligned with the causal closure of the universe and rejecting causally efficacious “exotic” properties. The foundational ontology is, in turn, monistic and materialistic, positing that the universe is composed solely of material particulars: bits of matter. In this work, we identify a notable tension between OP’s intended model and the one OP specifies. Initially, we show how the theory inevitably becomes entangled with higher-order entities, not just particulars. (...) Kim introduces the Supervenience Argument (SA) to counteract the possibility of higher-order entities being causally efficacious. While SA proves to be a plausible strategy, it is ultimately inadequate: not only SA is a petitio principii against emergence, but it is also unsound and invalid. Therefore, we propose a formal strategy to restore its ontological effectiveness. Unfortunately, at a closer look, even this strategy falls short as it unwarrantedly assumes the logicality and invariance of those equivalence relations (such as identity, similarity, and congruence) which are crucial for specifying the theory’s model as composed of particulars. (shrink)

This thesis is an investigation of the question of the probative force of the syllogism. It examines on what the probative force of propositions constituting an argument depends and some of the cases in which the conclusion of a syllogism is and is not proven by the premises. The investigation begins by looking at certain preliminary notions associated with arguments in general and categorical syllogisms in particular. In each categorical syllogism are found two claims. One is the claim to truth (...) made by each proposition, and another is the claim to validity made by the syllogism. When each of these claims are fulfilled the syllogism is then sound. The question is whether or not every sound syllogism also represents a proof of the conclusion. John Stuart Mill asserted that no deductive argument including the syllogism can be a proof of the truth of the conclusion on the grounds that the premises presuppose the conclusion. In fact each syllogism is an example of the fallacy of petitio principii which it must by its very nature commit. Alexander Pfänder instead claimed that only in certain cases is the conclusion not proven by the premises, while in other cases the truth of the conclusion is actually proven by the truth of the premises. An independent investigation of the question of the probative force of the syllogism is made. Because of a crucial difference between propositions affirming contingent states of fact and essentially necessary propositions affirming necessary states of fact, it is shown that no syllogism containing contingent propositions can be a proof, while a proof is present in the case of a syllogism containing essentially necessary propositions. When the propositions of an argument are contingent their truth follows from the fact each particular existing instance they refer to actually has what is affirmed by the proposition. Therefore, if the syllogism is valid, the conclusion will refer to at least some of the same particular existing instances on which the truth of each of the premises depends. The premises can be true only if the conclusion is true, and any uncertainty about the truth of the conclusion extends also to the premises. The premises cannot prove the truth of the conclusion since their truth presupposes the truth of the conclusion. Propositions which are essentially necessary are true regardless of whether or not any particular instance exists or will ever exist. Because the state of fact is essentially necessary, the predicate is intelligibly grounded necessarily in the subject. If these kinds of propositions are found in a syllogism, their truth will not depend on the truth of a conclusion. Essentially necessary propositions have probative force, and their presence in a valid argument results in an actual proof of the conclusion. (shrink)

Having, as it is generally agreed, failed to destroy the computational conception of mind with the G\"{o}delian attack he articulated in his {\em The Emperor's New Mind}, Penrose has returned, armed with a more elaborate and more fastidious G\"{o}delian case, expressed in and 3 of his {\em Shadows of the Mind}. The core argument in these chapters is enthymematic, and when formalized, a remarkable number of technical glitches come to light. Over and above these defects, the argument, at best, is (...) an instance of either the fallacy of denying the antecedent, the fallacy of {\em petitio principii}, or the fallacy of equivocation. More recently, writing in response to his critics in the electronic journal {\em Psyche}, Penrose has offered a G\"{o}delian case designed to improve on the version presented in {\em SOTM}. But this version is yet again another failure. In falling prey to the errors we uncover, Penrose's new G\"{o}delian case is unmasked as the same confused refrain J.R. Lucas initiated 35 years ago. (shrink)

Desarrollo varias hipótesis sobre los propósitos de la argumentación racional, parcialmente inspiradas en el análisis de Jackson sobre el concepto de petitio principii. Destaco como especialmente relevante entre tales propósitos la referencia a los potenciales destinatarios de una argumentación. Ilustro la discusión con un caso concreto: el argumento elaborado por Putnam para demostrar que no somos cerebros en una cubeta. Presento una versión de ese argumento y lo defiendo frente a una posible crítica que lo acusa de prejuzgar (...) la cuestión.I work out some hypothesis on the purposes of rational arguing, partly inspired by Jackson’s analysis of the concept of petitio principii. It is especially relevant among such purposes the reference to the potential intended addressee of an argument. The discussion is illustrated with a concrete example: Putnam’s proofthat we are not brains in a vat. I present a version of Putnam’s proof and defend it from a possible criticism which accuses it of begging the question. (shrink)

This paper is devoted to Kazimierz Twardowski's thesis that the unity of a compound object (a whole) can be ensured only by the relations between its parts and the object itself. Twardowski's idea of unity raises many difficulties, especially the threat of petitio principii: the whole is presupposed as furnishing the ground for the unification of its parts, and yet it also seems to be the result of this unification. To avoid these problems, Edmund Husserl sought to refute (...) Twardowski's thesis, and ascribed the role of a principle of unity to the foundational relationships which directly hold between the parts of a whole. Roman Ingarden then seemed to return to Twardowski's concept of unity, but employed it within a different theory of objects, according to which to be an object is to be a subject of properties. I seek to demonstrate that: (1) Twardowski's thesis is sound if a compound object is something over and above its parts; (2) with respect to Husserl's solution, it is not clear as to whether the whole is really something over and above its parts; (3) Ingarden's conception of the subject‐properties structure saves Twardowski's thesis; (4) Ingarden's theory of higher‐order objects is invalid. (shrink)

In Parts of Classes [Lewis 1991] David Lewis attempts to draw a sharp contrast between mereology and set theory and to assimilate mereology to logic. He argues that, like logic but unlike set theory, mereology is “ontologically innocent”. In mereology, given certain objects, no further ontological commitment is required for the existence of their sum. On the contrary, by accepting set theory, given certain objects, a further commitment is required for the existence of the set of them. The latter – (...) unlike the sum of the given objects – seems to be an abstract entity whose existence is not directly entailed by the existence of the objects themselves. The argument for the innocence of mereology is grounded on the thesis of “Composition as identity”. Lewis analyses two different versions of the thesis: the first is the Strong composition thesis, according to which certain objects are their sum, where the use of “are” would mean that composition is literally identity. The second version is the Weak composition thesis, according to which composition is analogous, under some aspects, to identity. He criticises the first version of the thesis and argues for the second one. In the paper we argue that (T1) arguments for the ontological innocence of mereology are not conclusive. An obvious objection to the Strong composition thesis is that – given certain objects Xs – they cannot be their sum because none of them is the sum. One could reply to this objection by observing that the “are” in the sentence “The Xs are their sum” is to be understood collectively and not distributively. But the crux is that the collective reading fails to generate a new entity, whereas mereology, in particular in Lewis’ use for the reconstruction of set theory as “megethology”, needs to consider sums as real objects. Besides, we contend that Lewis’ argument for the innocence of mereology based on the Weak composition thesis is a petitio principii. The reason is that the aspects of the analogy between composition and identity, which Lewis emphasises, obtain under the presupposition of the existence of sums. But this is just what a denier of innocence would refuse. (T2) Some arguments against the ontological innocence of mereology show a certain ambiguity in the innocence thesis itself. Some defences of the innocence seem to implicitly presuppose that the sum of certain objects Xs is not a genuine entity. Speaking of the sum of the Xs would be just another way of speaking plurally of the Xs. However, the relevant use of sums in mereology treats them as well determined objects. The relevant innocence thesis takes for granted that, though sums are genuine objects, nevertheless their existence does not require any further commitment. (T3) The innocence thesis, apart from Lewis’ defence, seems to depend on a general conception of the nature of objects and on how the notion of ontological commitment is understood. We think that the thesis is the manifesto of a realistic conception of parts and sums. This conception consists of the following clauses: (i) given any object x, it is well determined which parts it possesses; these are in turn objects whose existence is a necessary consequence of the existence of x. (ii) However any objects Xs are given, they automatically constitute a well determined object x which is their sum; (iii) We can refer singularly and plurally to parts and sums of given objects. Obviously, one might wonder if such a conception is really ontologically innocent. One could object that it is not innocent because clauses (i) – (iii) are not. For example, clause (i) could be considered as an ontological commitment to the existence of sums. But the innocence at issue does not concern the above-sketched conception. The innocence is embedded in the conception itself. In other words, someone who argues for clauses (i) – (iii) takes a point of view from which mereology appears to be innocent. For, such a point of view forces us to consider as well determined the parts of any object and does not allow us to separate the existence of certain objects form the existence of their sum. (T4) is the claim that the alleged innocence of mereology is subject to Quine’s notorious criticisms of the set-theoretical interpretation of second order logic. To the purpose, we construct a mereological model of a substantive fragment of set theory, i.e. the one that grounds the principal model semantics of second order logic. First, we construct a mereological model under the assumption of the existence of infinitely many atoms. Then, we replace this assumption with that of the existence of any infinite object (with or without atoms). Finally, let us make a general point about the innocence thesis of mereology. A conclusive argument for that would be a refutation of the thesis that there are only denumerably many entities. For, since the parts of an infinite object constitute a non-denumerable infinity, such an argument would entail that there could be no infinite without a non-denumerable infinity. However, the thesis that any genuine infinity is a denumerable one has had some important advocates. So, a conclusive argument for the innocence of mereology seems to be highly implausible. (shrink)

Marjorie Grene has argued in a number of contexts that any attempt to reduce the explanation of human actions to “mechanistic” explanations is doomed to failure in advance because it is absurd. “This argument examines the status of the reductivist thesis in its own terms and reduces it to absurdity …” ; “the attempt to reduce human purposive, or ‘intentional,‘ action to physiology and ultimately to physics and chemistry is an absurdity rather than simply a confusion”. I wish to show (...) that this argument is fallacious because it involves a petitio principii; and if Plato can be credited with introducing the same argument in the Theaetetus, as she suggests, so much the worse for Plato. (shrink)

Acquaintance with the name of argument against the vacuum, the present syllogism in René Descartes’ The Principles of Philosophy of 1644 must be extended to any form of continuum space. This article studies it from the point of view of Logic, with the purpose of revealing its petitio principii in relation with the analytical judgments. Hereby, as a result of review the foremost historic sources from where Kant obtains his famous division of the judgments in analytical and synthetic, (...) we will be able to understand the best method to discern about them and to demonstrate the subdivision that we need to establish inside the analytical judgments. (shrink)

In Protagoras 351b3‑358d4, Socrates apparently admits the use of pleasure and pain as criteria for distinguishing between good and bad. Focusing on this passage, my paper outlines three problems, raising from : the contradiction between Socrates’ objection to pleasure in other platonic dialogues and his assent here to a hypothesis which identifies good with pleasure ; the petitio principii apparently involved in Socrates’ argument to support the thought that knowledge is more powerful than emotions ; the compatibility of (...) his “ hedonist ” hypothesis with his “intellectualist” thought. My paper undertakes to reconstruct Socrates’ argument, in order to answer problem. I contend that this argument makes the humans admit they are deprived of the knowledge both of good and evil and of pleasant and painful, a point sufficient to silence them when they speak of “knowledge being defeated by pleasure”. This contention helps answering problem, through a distinction between so‑called pleasures and real ones. My conclusion answers problem, by showing that, held together, both the “hedonist” hypothesis and the “intellectualist” thought lead to not take pleasure for granted, as required to secure a philosophical approach. (shrink)

This study offers a new analysis of the last argument of Plato's Phaedo for the immortality of the soul. Interpretations of this argument and especially of the last section have differed considerably. Judgements on its value have usually been adverse. One scholar speaks of the ‘screen of unreal argument’ which concludes the proof, and writes that ‘from the standpoint of logic the argument has petered out into futility’. Another describes the final stage of the proof as ‘a blatant petitio (...) principii’. A third remarks that the conclusion follows ‘if we do not look too closely’. (shrink)

In diesem Aufsatz sollen einmal mehr zentrale Begründungsschritte im Ausweis der menschlichen Willensfreiheit in den Sektionen 2 und 3 von GMSIII untersucht werden, mit besonderer Berücksichtigung des in Sektion 3 formulierten Zirkels von Freiheit und Sittlichkeit. Das zentrale Ergebnis zur zweiten Sektion besagt, dass Kant dort keinen Beweis der menschlichen Willensfreiheit leistet, er vielmehr den eigentlichen Beweis, der in der dritten Sektion geleistet wird, bloß skizzierend vorwegnimmt. In der dritten Sektion liefert Kant eine geschlossene Argumentation von der notwendig anzunehmenden Vernünftigkeit (...) vernünftiger Wesen zur notwendigen Annahme transzendentaler Freiheit bis zur notwendigen Zuschreibung von Sittlichkeit, wobei der Schluss von der Freiheit der epistemischen Vernunft auf die praktischtranszendentale Freiheit geschieht. Dieser Befund ergibt sich zumindestdann, wenn man den Zirkel als eine eindeutige petitio principii liest, wofür auch sehr viel spricht. Allerdings ergeben sich in dieser Lesart Schwierigkeiten, Kants selbst formulierten Ausweg aus dem Zirkel zu interpretieren, wie er ihn am Ende der dritten Sektion formuliert. (shrink)

More than a century ago, G. E. Moore famously attempted to refute ethical naturalism by offering the so-called open question argument (OQA), also charging that all varieties of ethical naturalism commit the naturalistic fallacy. Although there is consensus that OQA and the naturalistic-fallacy charge both fail, OQA is sometimes vindicated, but only as an argument against naturalistic semantic analyses. The naturalistic-fallacy charge, by contrast, usually finds no takers at all. This paper provides new grounds for an OQA thus restricted. But (...) it aims chiefly at vindicating a version of the naturalistic fallacy, „the semantic-naturalist fallacy‟ (SNF), that we think defensible. We first argue that the openness of the question OQA raises against such analyses hinges on self-ascriptive, comparative judgments of content, which may be considered a priori warranted. We then provide independent reasons for the claim that the sort of mistake committed by naturalistic analyses in fact amounts to a pragmatic fallacy of a kind familiar in petitio principii and other forms of viciously circular inference. Of interest here are naturalistic analyses of ethical terms or concepts, not of properties. Our OQA (OQA*) raises an objection to the former. For no such semantic analyses can get off the ground unless moral terms are content-equivalent to purely descriptive terms, which amounts to saying that they must instantiate the same semantic types. Suppose „good‟ is the analysandum and „pleasure maximizing‟ the analysans (whichever purely descriptive term or terms would turn out to be the correct descriptive analysis of the target analysandum) of a certain semantic analysis. The claim that such terms are content-equivalent appears to be open to doubt on a priori grounds. After 1 all, whether one‟s own tokens of „good‟ and „pleasure maximizing‟ have/don‟t have the same content is a first-person, comparative judgment of content. Evaluating the proposed analysis requires, then, a self-ascriptive, comparative judgment of content.1 Judgments of this sort are thought to have a special epistemic status, since they seem grounded in neither evidence nor inference.. (shrink)

Term Functor Logic is a term logic that recovers some important features of the traditional, Aristotelian logic; however, it turns out that it does not preserve all of the Aristotelian properties a valid inference should have insofar as the class of theorems of Term Functor Logic includes some inferences that may be considered irrelevant (e.g. ex falso, verum ad, and petitio principii). By following an Aristotelian or syllogistic notion of relevance, in this contribution we adapt a tableaux method (...) for Term Functor Logic in order to avoid irrelevance and we offer some sort of intuitive semantics in terms of traditional inferential situations (e.g. propter quid, quia, non causa ut causa, and non sequitur). (shrink)

This paper undertakes two tasks. It will endeavour, first of all, to establish that there is a difficult discipline called Absolute-theory - Aristotle called it First Philosophy or Theology - which builds itself around the concept of a unique something which exists in an unqualified and necessary manner, and to which everything not itself attaches, or from which it in one manner or another derives. We shall try to distinguish the different strands or strata in the conception of an Absolute, (...) and shall then consider the alternative ways in which such a concept can be developed. For though, if there is or can be anything Absolute, it is one and unique and without rivals or alternatives, there are for us a large number of alternative ways of conceiving of what is absolute, some of which are arguably better and less exposed to antinomy than others. And of course there is always for us the alternative of not conceiving or not believing in any Absolute at all. And we shall briefly glance at the great historical dynasty of Absolutes: the infinitely arbitrary, anthropomorphic, of the Judaic-Christian-Islamic tradition, the less arbitrary Aristotelian-Neoplatonic Absolute of Thomas Aquinas, the Substantial Absolute of Spinoza, the Leibnizian-Wolffian Absolute of which Kant made his Ideal of Pure Reason, the Upanishadic Absolute of Shanaracharya, the infinitely vacuous Absolute of Mahayana Buddhism, the Deistic and Materialistic Absolutes of the Eighteenth Century Enlightenment, the absolute Space-Time of modern physicists, the Aussersein of Alexius Meinong and the Logical Space of Ludwig Wittgenstein. If the construction of Absolutes is an unrewarding language-and thought-game, it is none the less one which practically all the more intense thinkers have tried to play. I shall next, in the second part of my paper, try to establish that Hegel is by far the subtlest and the most successful of all the Absolute-theorists. His whole philosophy may be regarded as an essay in Absolute-theory, in that it throughout does nothing but try out, modify or discard categories of thought and forms of being because they fail to measure up to an adequate conception of an Absolute. And in his vast rehearsal of categories and forms of being Hegel arguably works up to a conception of the Absolute which takes account of a far wider and richer array of issues, and forestalls a more varied assemblage of objections than any other exercise in Absolute-theory. Sometimes Hegel anticipates thought-moves that will occur long after his death: the moves, e.g., of John Stuart Mill regarding the Syllogism’s being a Petitio Principii, and inductive reasoning’s being really an inference from particulars to particulars. And it will be our contention, finally, that Hegel is by far the most successful of Absolutists, in that he, and he alone, has worked out a many-sided Logic which, whatever its imperfections, is the only sort of instrument with which Absolute-theory can be tackled. In arguing in this manner I shall be contributing to the main theme of this Congress, the nature of the Universe, for the Universe, I believe, is a very vague and degenerate sort of Absolute. (shrink)