The present article deals with the not very common opinion among medieval philosophers according to which the identity principle is the true first principle, undermining the primacy of the principle of non-contradiction. Following a refutation of this position in the logical work of the Franciscan Geraldus Odonis, we intend to investigate its target as well as other cases of the same dispute in 14th century authors: Antoine Andre, John of Buridan, John of Baconthorpe and Nicolas of (...) Autrecourt. We defend that Odonis presents a successful response to this position. (shrink)

Leibniz was a philosopher of principles: the principles of Contradiction, of Sufficient Reason, of Identity of Indiscernibles, of Plenitude, of the Best, and of Continuity are among the most famous Leibnizian principles. In this article I shall focus on the first three principles; I shall discuss various formulations of the principles (sect. 1), what it means for these theses to have the status of principles or axioms in Leibniz’s philosophy (sect. 2), the fundamental character of the Principles of Contradiction (...) and Sufficient Reason (sect. 3), some attempts to demonstrate the Principles of Contradiction and Sufficient Reason (sect. 4), and one attempt to demonstrate the Principle of Identity of Indiscernibles (sect. 5). The main results of the chapter are summarized in a short conclusion (sect. 6). (shrink)

I argue that, despite van Inwagen’s pessimism about the task, it is worth looking for answers to his General Composition Question. Such answers or ‘principles of composition’ tell us about the relationship between an object and its parts. I compare principles of composition with criteria of identity, arguing that, just as different sorts of thing satisfy different criteria of identity, they may satisfy different principles of composition. Variety in criteria of identity is not taken to reflect ontological (...) variety in the identity relation; I discuss whether variety in principles of composition should be taken to reflect ontological variety in the composition relation. (shrink)

It is argued that recent discussion of the principle of the identity of indiscernibles (PII) and quantum mechanics has lost sight of the broader philosophical motivation and significance of PII and that the `received view' of the status of PII in the light of quantum mechanics survives recent criticisms of it by Muller, Saunders, and Seevinck.

In 1907 Einstein had the insight that bodies in free fall do not “feel” their own weight. This has been formalized in what is called “the principle of equivalence.” The principle motivated a critical analysis of the Newtonian and special-relativistic concepts of inertia, and it was indispensable to Einstein’s development of his theory of gravitation. A great deal has been written about the principle. Nearly all of this work has focused on the content of the principle (...) and whether it has any content in Einsteinian gravitation, but more remains to be said about its methodological role in the development of the theory. I argue that the principle should be understood as a kind of foundational principle known as a criterion of identity. This work extends and substantiates a recent account of the notion of a criterion of identity by William Demopoulos. Demopoulos argues that the notion can be employed more widely than in the foundations of arithmetic and that we see this in the development of physical theories, in particular space–time theories. This new account forms the basis of a general framework for applying a number of mathematical theories and for distinguishing between applied mathematical theories that are and are not empirically constrained. (shrink)

Most analysts agree that democratic theorists have not offered a persuasive answer to the question of how the boundaries of a demos, a democratic people, should legitimately be defined. Some contend that boundaries should be maintained in ways that preserve sufficient sense of common identity to sustain support for redistributive policies. Many others endorse the “principle of all affected interests,” but it has been widely criticized as unrealistically destructive of too many existing community boundaries. This essay argues for (...) an alternative “principle of constituted identities.” It holds that, subject to certain important qualifications, modern constitutional democracies, at least, are morally obligated to extend the option of full membership to all those whose identities have been substantially constituted through such regimes’ coercive policies. Keywords : civic boundaries; principle of affected interests; constitutional democracy; stories of peoplehood; cultural identity (Published online: 25 August, 2008) Citation: Ethics & Global Politics 2008. DOI: 10.3402/egp.v1i3.1860. (shrink)

Can the persistence of a human being's soul at death and prior to the bodily resurrection be sufficient to guarantee that the resurrected human being is numerically identical to the human being who died? According to Thomas Aquinas, it can. Yet, given that Aquinas holds that the human being is identical to the composite of soul and body and ceases to exist at death, it's difficult to see how he can maintain this view. In this paper, I address Aquinas's response (...) to this objection . After making a crucial clarification concerning the nature of the non-repeatability principle on which the objection relies, I argue that the contemporary notion of immanent causal relations provides us with a way of understanding Aquinas's defence that renders it both highly interesting and philosophically plausible. (shrink)

This paper concerns the question of whether Pauli's Exclusion Principle (EP) vindicates the contingent truth of Leibniz's Principle of the Identity of Indiscernibles (PII) for fermions as H. Weyl first suggested with the nomenclature ‘Pauli–Leibniz principle’. This claim has been challenged by a time-honoured argument, originally due to H. Margenau and further articulated and champione by other authors. According to this argument, the Exclusion Principle—far from vindicating Leibniz's principle—would refute it, since the same reduced (...) state, viz. an improper mixture, can be assigned as a separate state to each fermion of a composite system in antisymmetric state. As a result, the two fermions do have the same monadic state-dependent properties and hence are indiscernibles. PII would then be refuted in its strong version (viz. for monadic properties). I shall argue that a misleading assumption underlies Margenau's argument: in the case of two fermions in antisymmetric state, no separate states should be invoked since the states of the two particles are entangled and the improper mixture—assigned to each fermion by reduction—cannot be taken as an ontologically separate state nor consequently as encoding monadic properties. I shall then conclude that the notion of monadic properties together with the strong version of PII are inapplicable to fermions in antisymmetric state and this undercuts Margenau's argument. (shrink)

After sketching some aspects of truthmaker doctrines and "truthmaker projects", and canvassing some prima facie objections to the latter, I turn to an issue which might seem to involve confusion about the nature of character of truthmakers if such there be, viz for statements of identity and (specially) distinctness. The real issue here is versions of the Identity of Indiscernibles. I discuss ways of discriminating versions, which are almost certainly true but trivial, which almost certainly substantive but false, (...) and explore an interesting intermediate possibility which might if developed yield a plausibly true yet not-entirely-trivial version of the doctrine: it is equivalent to what I call "the Denial of Bare Distinctness". (shrink)

This book brings together the debate concerning personal identity and central topics in biomedical ethics. Based on a metaphysical account of personal identity in the sense of persistence and conditions for human beings, conceptions for beginning of life, and death are developed. Based on a biographical account of personality, normative questions concerning autonomy, euthanasia, living wills and medical paternalism are dealt with. By these means the book shows that “personal identity” has different meanings which have to be (...) distinguished so that human persistence and personality can be used to deal with central questions in biomedical ethics. (shrink)

Mill’s proscription that ‘the only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others’ has become almost axiomatic in bioethics. 1 Bolstered by the rise of patient autonomy during the mid-20th century, Millian conceptions of freedom have become so embedded in bioethical theory, that attempts to justify paternalism have typically involved making one of two claims. Either, they have involved refuting the significance of autonomy as (...) an ethical principle, and questioning whether it should always be taken to outweigh other ethical principles. Or, they have sought to cast doubt on the autonomous quality of specific decisions, challenging them as non-autonomous in some important way. Both approaches are readily apparent in discussions about the moral authority of advance directives, where people have questioned both whether precedent autonomy should always outweigh the person’s current best... (shrink)

There is a certain argument against the principle of the indiscernibility of identicals, or the thesis that whatever is true of a thing is true of anything identical with that thing. In this argument, PInI is used together with the self-evident principle of the necessity of self-identity to reach the conclusion, which is held to be paradoxical and, thus, fatal to PInI. My purpose is to show that the argument in question does not have this consequence. Further, (...) I argue that PInI is a universally valid principle which can be used to prove the necessity of identity. (shrink)

Gonzalo Rodriguez-Pereyra presents an original study of the place and role of the Identity of Indiscernibles in Leibniz's philosophy. The Principle of the Identity of Indiscernibles rules out numerically distinct but perfectly similar things; Leibniz derived it from more basic principles and used it to establish important philosophical theses. Rodriguez-Pereyra aims to establish what Leibniz meant by the Principle of Identity of Indiscernibles, what his arguments for and from it were, and to assess those arguments (...) and Leibniz's claims about the Principle of Identity of Indiscernibles. He argues that Leibniz had a very strong version of the principle, according to which no possibilia are intrinsically perfectly similar, where this excludes things that differ in magnitude alone. The book discusses Leibniz's arguments for the Identity of Indiscernibles in the Meditation on the Principle of the Individual, the Discourse on Metaphysics, Notationes Generales, Primary Truths, the letter to Casati of 1689, the correspondence with Clarke, as well as the use of the Identity of Indiscernibles in Leibniz's arguments against the Cartesian conception of the material world, atoms, absolute space and time, the Lockean conception of the mind as a tabula rasa, and freedom of indifference. Rodriguez-Pereyra argues that the Identity of Indiscernibles was a central but inessential principle of Leibniz's philosophy. (shrink)

we propose a revised version of Black's original argument against the principle of identity of indiscernibles. Our aim is to examine a puzzle regarding the intuitiveness of arguments, by showing that the revised version is clearly less intuitive than Black's original one, and appears to be unjustified by our ordinary means of assessment of intuitions.

We show that short bounded-depth Frege proofs of matrix identities, such as PQ=I⊃QP=I (over the field of two elements), imply short bounded-depth Frege proofs of the pigeonhole principle. Since the latter principle is known to require exponential-size bounded-depth Frege proofs, it follows that the propositional version of the matrix principle also requires bounded-depth Frege proofs of exponential size.

This article discusses Heidegger’s interpretation of Parmenides given in his last public lecture ‘The Principle of Identity’ in 1957. The aim of the piece is to illustrate just how original and significant Heidegger’s reading of Parmenides and the principle of identity is, within the history of Philosophy. Thus the article will examine the traditional metaphysical interpretation of Parmenides and consider G.W.F. Hegel and William James’ account of the principle of identity in light of this. (...) It will then consider Heidegger’s contribution, his return to and re-interpretation of Parmenides in his last lecture. Heidegger will, through the Parmenidean claim that ‘Thinking and Being are one’ deconstruct the traditional metaphysical understanding of the principle of identity, and in its place offer a radically different conception of how our relationship, our ‘belonging together’ with Being can be understood. (shrink)

The aim of this paper is to derive a perfectly general criterion of identity through time from Locke’s Principle, which says that two things of the same kind cannot occupy the same space at the same time. In this way, the paper pursues a suggestion made by Peter F. Strawson almost thirty years ago in an article called ‘Entity and Identity’. The reason why the potential of this suggestion has so far remained unrealized is twofold: firstly, the (...) suggestion was never properly developed by Strawson, and secondly, it seemed vulnerable to an objection that he himself raised against it. Consequently, the paper’s aim is to further develop Strawson’s suggestion, and to show that the result is not vulnerable to the objection that seemed fatal to its underdeveloped predecessor. In addition, the paper aims to defend Locke’s Principle against alleged counterexamples such as those produced by Leibniz, Fine and Hughes. (shrink)

In this paper we study the notion of $C^{}$ -supercompactness introduced by Bagaria in [3] and prove the identity crises phenomenon for such class. Specifically, we show that consistently the least supercompact is strictly below the least $C^{}$ -supercompact but also that the least supercompact is $C^{}$ -supercompact }$ -supercompact). Furthermore, we prove that under suitable hypothesis the ultimate identity crises is also possible. These results solve several questions posed by Bagaria and Tsaprounis.

Is it ethical for doctors or courts to prevent patients from making choices that will cause significant harm to themselves in the future? According to an important liberal principle the only justification for infringing the liberty of an individual is to prevent harm to others; harm to the self does not suffice.In this paper, I explore Derek Parfit’s arguments that blur the sharp line between harm to self and others. I analyse cases of treatment refusal by capacitous patients and (...) describe different forms of paternalism arising from a reductionist view of personal identity. I outline an Identity Relative Paternalistic Intervention Principle for determining when we should disallow refusal of treatment where the harm will be accrued by a future self, and consider objections including vagueness and non-identity.Identity relative paternalism does not always justify intervention to prevent harm to future selves. However, there is a stronger ethical case for doing so than is often recognised. (shrink)

이 논문은 아도르노 철학의 핵심 문제 중 하나인 정신과 자연의 화해가능성을 해명하기 위하여 정신을 동일성 및 친화성 원칙 속에서 규정한다. 이를 위한 근거가 되는 것은 정신의 자연사적 기원에 관한 아도르노의 두 가지 테제(“정신은 자기보존에서 발생했다”와 “미메시스는 정신의 생리학적 전형식이다”)이며, 이에 따라 정신은 각각 동일성 그리고 친화성 원칙 속에서 파악될 수 있다. 상세한 고찰 속에서 밝혀질 바는 이 개념들의 양의성 및 상호지시성이다. 아도르노에게 있어 동일성은 자기보존 및 자연지배의 수단이지만 동시에 화해적 잠재력의 담지자라는 이중의 사실을 의미한다. 그러나 동일성의 틀 안에 갇혀 있는 (...) 한 정신은 자신과 타자의 근원적 관계를 충분히 자각할 수 없다는 한계에 노출된다. 마찬가지로 친화성 개념 또한 이중적인데, 한편으로 그것은 합리성의 타자로서 퇴행을 의미하지만 다른 한편 동일성 정신을 질적으로 변화시킴으로써 그것을 타락에서 구제해줄 해방의 계기이기 때문이다. 그러나 친화성, 미메시스적 태도는 특유의 맹목성으로 인하여 혼자서는 결코 화해와 해방을 보증할 수 없다. 이러한 양의성은 따라서 동일성 정신의 자기 반성과 타자에로의 개방은 함께 이루어져야만 함을 암시한다. 즉 아도르노는 저 두 가지의 과제가 하나의 정신이 수행하는 하나의 행위임을 보고 있는 것이다. 오직 이속에서만 자연과의 화해를 통한 정신의 자기 해방이 가능해진다. (shrink)

As a self-conscious religious collective with minority status, Jews seeking recognition in the modem nation-state have had to fashion not just principles of belief, but also a narrative to articulate the historical essence of their existence. The most common narrative of the twentieth century has been a story, not a myth—a story, moreover, with limited capacity for interfaith dialogue. By the end of the century, that story began to lose its compelling quality. The twenty-first century demands a return to myth, (...) with the promise of more promising theological conversation across faith lines. (shrink)

Faced with strong arguments to the effect that Leibniz''sPrinciple of the Identity of Indiscernibles (PII) is not a necessary truth, many supporters of the Principle have staged a strategic retreat to the claim that it is contingently true in this, the actual, world. The purpose of this paper is to examine the status of the various forms of PII in both classical and quantum physics, and it is concluded that this latter view is at best doubtful, at worst, (...) simply wrong. (shrink)

According to Locke’s Principle, material objects are identical if and only if they are of the same kind and once occupy the same place at the same time. There is disagreement about whether this principle is true, but what is seldom disputed is that, even if true, the principle fails to constitute an applicable criterion of identity. In this paper, I take issue with two arguments that have been offered in support of this claim by arguing (...) (i) that we can have knowledge of past whereabouts, and so verify the right hand side of Locke’s Principle, without having to assess concrete identity claims first; (ii) that even under conditions of incomplete knowledge of past whereabouts we can use Locke’s Principle to decide concrete identity problems. (shrink)

Suppose we discover how we could live for a thousand years, but in a way that made us unable to have children. Everyone chooses to live these long lives. After we all die, human history ends, since there would be no future people. Would that be bad? Would we have acted wrongly? Some pessimists would answer No. These people are saddened by the suffering in most people’s lives, and they believe it would be wrong to inflict such suffering on others (...) by having children. In earlier centuries, this bleak view was fairly plausible. But our successors would be able to prevent most human suffering. Some optimists would also answer No . . . These [views] are, I believe, deeply mistaken. Given what our successors could achieve in the next million or billion years, here and elsewhere in our galaxy, it would be likely to be very much worse if there were no future people. (shrink)

Searle's (1990) argument for the seems to rest on a confusion between ontological and epistemological claims. The potential consciousness of a mental state does not yield the same effect as does its actual consciousness, namely, the preservation of aspectual shape. Searle's distinction between the consciousness of an intentional object and that of a mental state, which is meant to counter the objection that deep unconscious rules cease to be deep once they become conscious, fails to do its appointed task.

The Principle of the Identity of Indiscernibles —the principle that no two numerically distinct things are perfectly similar—features prominently in Leibniz’s metaphysics. Despite its centrality to his philosophical system, it is surprisingly difficult to determine what modal status Leibniz ascribes to the PII. On many occasions Leibniz appears to endorse the necessity of the PII. There are a number of passages,however, where Leibniz seems to imply that numerically distinct indiscernibles are possible, which suggests that he subscribes to (...) a merely contingent version of the PII. In this paper I attempt to resolve this apparent inconsistency. I argue that Leibniz consistently takes the PII to be necessary and that this view of his shines through even in his correspondence with Clarke. I also show that competing interpretations, on which Leibniz’s PII is contingent, misread a number of crucial passages from this correspondence. (shrink)

In the literature on multiple realizability and the identity theory, cases of neural plasticity have enjoyed a very limited role. The present article attempts to remedy this small influence by arguing that clinical and experimental evidence of quite extensive neural reorganization offers compelling support for the claim that psychological kinds are multiply realized in neurological kinds, thus undermining the identity theory. In particular, cases are presented where subjects with no measurable psychological deficits also have vast, though gradually received, (...) neurological damage. Common objections and concerns are also discussed and rejected. 1 Introduction2 The GRP, Serial Lesion Effect, and Multiple Realizability2.1 A case study of the serial lesion effect2.2 Evaluating the case study’s evidence for multiple realizability3 The GRP More Generally4 Objections to the GRP as Evidence for Multiple Realizability4.1 Small plastic effects and neurological taxonomies4.2 But do neural regions and locations even matter at all?4.3 But are there not other options besides location?5 Conclusion. (shrink)

In considering the possibility that the fundamental particles of matter might violate Leibniz's Principle, one is confronted with logical proofs that the Principle is a Theorem of Logic. This paper shows that the proof of that theorem is not universal enough to encompass entities that might not be unique, and also strongly suggests that photons, for example, do violate Leibniz's Principle. It also shows that the existence of non-individuals would imply the breakdown of Quine's criterion of ontological (...) commitment. (shrink)

The aim of this paper is to render a detailed analysis of the correspondence with Clarke in order to shed some light in the relationship between the Principle of Identity of Indiscernibles and the Principle of Sufficient Reason. Most of the secondary literature takes for granted that Leibniz derives the Principle of Identity of Indiscernible from the Principle of Sufficient Reason in at least some parts of the correspondence. This would render the Principle (...) of Identity of Indiscernibles a merely contingent truth and not a necessary principle. I will argue that this interpretation is misleading, and that Leibniz never abandoned the idea that the Principle of Identity of Indiscernibles is a necessary truth. Although he is continuously using the Principle of Sufficient Reason in his argumentation, he keeps in parallel a strong argumentation that entails the necessity of the Principle of Identity of Indiscernibles. To achieve this goal, it will be necessary to point out first some contextual facts that may determine a correct understanding of the correspondence. It will be also necessary to frame the discussion about the principles into the broader debate on the possibility of Newtonian space. Finally, it will be shown that the mentioned hypothesis is supported by textual evidence throughout the entire correspondence. (shrink)

Contact between culturally distinct human groups in the contemporary ‘glocal’ -global and local- world is much greater than at any point in history. The challenge we face is the identification of the most convenient ways to organise the coexistence of different human language groups in order that we might promote their solidarity as members of the same culturally developed biological species. Processes of economic and political integration currently in motion are seeing increasing numbers of people seeking to become polyglots. Thus, (...) English is establishing itself as the usual world supra-language, although it coexists with other lingua francas that are widely used in certain parts of the globe. All this communicative reorganization of the human species may very well pose new problems and aggravate existing tensions as regards language and identity. It would seem that these processes comprise at least four major conceptual dimensions which must be taken into account above all else, as they are both widespread and, left unaddressed, may lead to significant social instability. These dimensions concern linguistic recognition, communicability, sustainability and integration. While accepting the utility of having an inter-national language, the keystone of the system is clearly that it must ensure the linguistic sustainability of each group. The basic principle is likely to be functional subsidiarity, i.e., whatever can be done by the local language should not be done by another one which is more global. As in the quote from Paracelsus --“the dose alone makes the poison”-- contact between languages is not ‘poisonous’ per se, but when the correct dose is exceeded it can prove harmful to the language whose position is weaker. A multilingual and communicated humanity is possible. (shrink)

본 연구는 논리학 및 수리논리학의 토대 개념인 동일성 원리에 대한 역사적인 논쟁들의 교육학적 함의를 도출하는 것이다. 이때 필자가 사용할 중심 방법은 구조-구성주의 인식론이다. 따라서 필자는 구조-구성주의 인식론의 관점에서 동일성 원리에 대한 핵심 논쟁들을 역사-비판적으로 재구성함으로써, 필자가 지속적으로 논변해 온 구조-구성주의 교수학습이론의 확고한 토대를 제공하고자 한다. 이를 위해 본고는 동일성 원리에 대한 역사발생학적 탐구와 정신발생학적 탐구를 종합한다. 구체적인 내용은 피아제의 발생학적 인식론의 관점에서 논리적 개념들 및 공리화에 대한 프레게-러셀의 선험주의적 논리주의와 비트겐슈타인의 회의론적 유명론을 동시에 비판하면서, 구조-구성주의 인식론 및 이것의 교육학적 함의를 (...) 도출하는 것이다. 본고의 최종 결론은 이것이다. 논리적 법칙 또는 공리들은 초인적인 논리학자의 선험적인 직관에 의해서 구성된 것도 아니고, 유명론적 입장의 순수 기호게임으로 환원되는 것도 아니라, 정신 발달과 함께 발달되는 주체와 대상의 상호작용의 결과물, 즉 조작적 구조들의 형식화에 근거한다. 따라서 논리학적 개념들뿐만 아니라, 모든 일반적인 개념을 교육할 때, 교사는 실체와 술어, 개념과 판단, 판단과 추론 사이에 성립되는 미시적 상호의존성과 순환성뿐만 아니라, 이들 전체들 사이에 성립하는 거시적 상호의 존성과 순환성을 동시에 고려해야 한다. (shrink)

The relationship of the identity of indiscernibles principle to other major metaphysical principles (e.g., relational doctrine of space and time, elimination of singular terms) is discussed, the aim being to outline the necessary requirements of a systematic metaphysics incorporating the former principle. the conclusion is that no adequate systematic metaphysics of this sort is defensible. throughout special attention is paid to modern logical formulation of the principle and to its role in quine's philosophy.

The first principle of Fichte’s philosophy, the Wissenschaftslehre, is “I am,” whereas the logical principle of identity is “A is A.” The relationship of Fichte’s philosophy to logic helps us understand the relation between the principles of these two disciplines. The first principle of the Wissenschaftslehre as an Act (Thathandlung) is the ground of consciousness and therefore renders logic possible as a science. Even though logic is grounded on the Wissenschaftslehre, the form of logic is used (...) by the latter to comprehend itself. The difference between logic and the Wissenschaftslehre consists in the fact that the former merely supplies a form and the latter contains both the form and the content. Logic arises from the Wissenschaftslehre through the free acts termed “abstraction” and “reflection.” In the Wissenschaftslehre, the form of logical propositions as equality, affirmation and substitution, are derived from the primordial act of the self-positing of the I. (shrink)

We discuss some logico-mathematical systems which deviate from classical logic and mathematics with respect to the concept of identity. In the first part of the paper we present very general formulations of the principle of identity and show how they can be ‘relativized’ to objects and to properties. Then, as an application, we study the particular cases of physics and logic . In the last part of the paper, we discuss the alphabar logics, that is, those logical (...) systems which violate a formulation of one of the most fundamental versions of the principle of identity; in these logics, there are formulas which are not deducible from themselves. (shrink)

Klimuk I. M. The methodological principles of the study of religious identity.The article deals with the problem of religious identity, which become more intense in the world and needs to determine the principles of the study of this phenomenon.

La plupart des commentateurs interprète le principe de l'identité des indiscernables comme principe purement logique, mais avec des implications métaphysiques, et donc, selon l'interprétation commune, comme fausseté ou vérité contingente ou triviale. Je soutiens, au contraire, que le principe, selon Leibniz, est vrai, mais que cette vérité n'est triviale ni contingente, mais nécessaire dans un sens métaphysique. Leibniz tent à démontrer la nécessité du principe dans deux manières : une manière logique et une manière métaphysique . Je soutiens que seule (...) la manière métaphysique peut réussir, et que la négligeance de cette manière aboutit au malentendu de ce principe. (shrink)