UMA DEFESA INDUTIVISTA BOTTOM-UP DO REALISMO CIENTÍFICO EPISTEMOLÓGICO, 2023
Neste artigo, apresento uma defesa do realismo científico epistemológico, segundo a qual temos ma... more Neste artigo, apresento uma defesa do realismo científico epistemológico, segundo a qual temos mais razões para acreditar na realidade das entidades detectadas e na verdade aproximada das proposições sobre elas. Minha defesa é diferente das estratégias explicativas usuais. Em vez de desenvolver uma argumentação explicativa top-down, que consiste em avaliar os méritos de várias explicações de fenômenos e, em seguida, decretar que a melhor explicação provavelmente será verdadeira, oferecerei um argumento bottom-up que parte de observações para ascender às causas que as produzem. Embora essas causas não sejam diretamente observadas, temos boas razões para acreditar em sua existência se forem detectadas, ou seja, se estiverem causalmente ligadas a observações diretas. Essa abordagem bottom-up tem a vantagem de não ser vulnerável às objeções levantadas contra a inferência da melhor explicação. Para ilustrar esse ponto, argumentarei que o famoso argumento de Le Verrier para a existência de Netuno é convincente precisamente porque implementa essa estratégia bottom-up.
Mechanistic Explanations in Physics and Beyond, 2019
The present paper critically examines the main claims of the new mechanist account of explanation... more The present paper critically examines the main claims of the new mechanist account of explanation defended by Glennan and Machamer, among others. The two major difficulties of the new mechanism, namely the circularity objection and the bottoming out problem are discussed and addressed. To solve the bottoming out problem, this paper proposes a modification and enlargement of the mechanist account of explanation advocated by Salmon and Dowe. Such extension can then successfully apply to the explanations provided for the global behaviour of complex systems, not only in physics but also in other disciplines such as biology and the social sciences. The proposed enlarged version of Salmon’s and Dowe’s account provides a monistic account of explanation based on causal generalizations or laws which need not be construed as necessary to fulfil their explanatory role. Such change-relating generalizations or laws are characterized by the presence of a term that refers to the variation in time of some property, which is identified to the effect whereas the other terms refer to the causes. Thus, by enlarging the Salmon and Dowe notion of mechanism, I advocate a nomological theory of causation instead of the mechanistic theory of causation proposed by Glennan et alii.
Book review published in Metascience online October 2017 of Jean Bricmont's
Making sense of qua... more Book review published in Metascience online October 2017 of Jean Bricmont's
Explanationist strategies for defending epistemological scientific realism (ESR) make heavy use o... more Explanationist strategies for defending epistemological scientific realism (ESR) make heavy use of a particular version of inference to the best explanation (IBE) known as the no-miracle argument (NMA). I consider ESR to be a genuinely philosophical-non-naturalistic – thesis which contends that there are strong arguments to believe in some non-observational claims made by scientific theories that are partially predictively correct. In this paper, I examine the grounds of the strength of these arguments from what I call a contemplative perspective which focuses on the end products, i.e. theories, of the scientific activity as opposed to the pragmatist view which considers science to be primarily an activity. I briefly rehearse the main difficulties of the no-miracle argument and of inference to the best explanation in general. I argue that a convincing defence of ESR should be based on the empirically ascertained reality of causal connections between theoretical entities which possess properties that are in principle observable (OP properties) and the results of measurements or observations. The knowledge of those causal connections may well deliver an – even the best – explanation of the appearances. But belief in the existence of some unobservable entities is mainly justified by their empirically attested causal role, not on their possible explanatory function.
In this paper I advocate a version of selective epistemological realism. I begin with analyzing t... more In this paper I advocate a version of selective epistemological realism. I begin with analyzing the conditions in which a scientific model successfully and correctly represents an identified target. I stress that the realistic import of models rests on the truth of some predicative statements. I then examine the notions of objectivity and truth in order to be able to assess the reasons to believe in the existence of some unobserved objects posited by our best scientific theories and in the truth of some assertions about the properties that these objects possess. I distinguish between the properties that are observable in principle by means of instruments which enhance our perceptive capacities (the OP properties) and the properties that are beyond any possible observation by us, namely the properties which are purely theoretical (the PT properties), such as charm and strangeness in elementary particle physics. The OP properties are identical or similar to the observed properties of ordinary perceived things, such as velocity, volume and, admittedly more controversially, charge and mass. I propose four stringent requirements for rationally believing that an unobserved object posited by a theory possesses a specific property. Firstly, this property must be an OP property. Secondly, it must be measurable. Thirdly, it must play a causal role in producing the observed data. Fourthly, distinct independent methods for measuring this property must deliver concordant results. I then show that the generality and acceptability of these four criteria is grounded on a parallelism with the reasons we adduce for (rightly) believing in the existence of ordinary observable things which we don’t immediately perceive such as mice, in some circumstances. However, an agnostic attitude is to be recommended with respect to the possession of PT properties by an object posited by an - even successful - scientific theory.
In his Scientific Representation. Paradoxes of Perspective (2008), Bas van Fraassen offers a prag... more In his Scientific Representation. Paradoxes of Perspective (2008), Bas van Fraassen offers a pragmatic account of scientific representation and representation tout court. In this paper I examine the three conditions for a user to succeed in representing a target in some context: identification of the target of the representational action, representing the target as such and such and correctly representing it in some respects. I argue that success on these three counts relies on the supposed truth of some predicative assertions, and thus that truth is more fundamental than representation. I do this in the framework of a version of the so-called " structural " account of representation according to which the establishment of a homomorphism by the user between a structure abstracted from the intended target and some relevant structure of the representing artefact is a necessary (although certainly not sufficient) condition of success for representing the target in some respects. Finally, on the basis of a correspondence view (not theory) of truth, I show that it is possible to address what van Fraassen calls " the loss of reality objection ". In his book Scientific Representation. Paradoxes of Perspective (2008) Bas van Fraassen offers a philosophical analysis of representation which is both empiricist and pragmatic. To represent is to perform some kind of action, and actions are evaluated with respect to their success or failure in attaining specific goals. Moreover, in science success or failure in representing a target must be assessed on the basis of observable phenomena. As is well known, according to van Fraassen, science aims at empirical adequacy, that is, at saving the phenomena. Thus, a scientific theory is successful if we have good reasons to believe that it saves the phenomena within its domain. Since for van Fraassen scientific theories are models in the first place, a theory is successful if its empirical parts, called " empirical substructures " , adequately represent the phenomena within its domain. A satisfactory account of representation is thus central to van Fraassen's philosophy of science. The success of a representational action can be evaluated on three counts. First, the user of a representing artefact must succeed in identifying its target or referent. Second, the target is always represented from a certain perspective as having such and such properties. Third, we may ask if our representing activity conveys some reliable information about its target or, in other words, if our representing artefact (a scientific model for example) is adequate or accurate to its target in some respects.
In this important book, which is the outcome of several decades of intense philosophical activity... more In this important book, which is the outcome of several decades of intense philosophical activity, Evandro Agazzi offers a rigorous argumentation in favour of an original conception of scientific realism and objectivity in science. The book begins with an analysis of the origin of what the author calls “dualism” – both in its ontological and epistemological versions (29) – in which he correctly locates the source of contemporary relativist and antirealist views on science. Ontological dualism goes back to the ancient Greeks and divides the world into “surface appearances” and “deep authentic realities”. In its epistemological version, dualism appears with the birth of modern science in the 17th century. Epistemological dualism postulates a dichotomy between our ideas or mental representations, which are supposedly immediately known to us, and reality itself. Such division raises the question of the faithfulness of our representations to the realities which they are meant to represent (245). But this problem has no satisfactory solution. Once a wedge is driven between ideas and things, we are inevitably drawn to a sceptical attitude with respect to science’s capacity to reach knowledge of reality. By embracing a realist position, Agazzi stands against dualism: science aims at knowing what is real, including some unobservable entities, and manages to do so, albeit only partially.
1. The problem of identii cation and the problem of inference A main issue in the literature on l... more 1. The problem of identii cation and the problem of inference A main issue in the literature on laws is to dee ne criteria which would permit to distinguish genuine lawlike propositions from universally true propositions which describe merely accidental or fortuitous regularities in the world, such as all gold objects have a mass inferior to fty tons, to reformulate a well-known example due to Hans Reichenbach. This is the epistemological problem of identii cation. The challenge here is to formulate criteria, in the sense of suff cient conditions at least, which would justify attributing the title of law to a universally true proposition. If those criteria are satiss ed by the proposition, then we know that it is a law and that it does not just happen to be accidentally true. This is the task that Humean regularists set to themselves. Since, for them, lawlike propositions describe worldly regularities, their aim is to nd criteria which are consistent with their empiricist position and to refrain from introducing ingredients which would go beyond the realm of what is empirically accessible. In other words, serious empiricists are required to shun any kind of metaphysics. As we will see such endeavor is fraught with all sorts of diff culties. On this I agree with van Fraassen who is, in his own words, a " immoderate empiricist " (2000, 1660) and consistently sustains that there are no laws, in the sense that the search for empirically satisfactory criteria which would divide regularities into two distinct classes, lawful and unlawful, is bound to fail. Simply because there is no empirical fact, that is, some empirically detectable special kind of regularities, which would legitimate endowing the propositions which describe them with the title of law. Surely, some regularities are more general than others, but they all are regularities in the rst place and no empirical feature is available which would permit to single out some regularities and endow them with some privileged status. This is why the empiricists who would like to retain the distinction between laws and non-laws, just as scientists do, attempted to devise criteria which are internal to
After a presentation of some relevant aspects of Anjan Chakravartty’s semirealism (2007), this pa... more After a presentation of some relevant aspects of Anjan Chakravartty’s semirealism (2007), this paper addresses two difficulties that appear to be inherent to important components of his proposed metaphysics for scientific realism. First, if particulars and laws are concrete structures, namely actual groupings of causal properties as the semirealist contends, the relation between particulars and laws becomes also a relation between particulars with some annoying consequences. This worry – and some others - are resolved if laws are taken to be statements and particulars are construed not only as groupings of properties, but things that contain a non-conceptual ingredient which can be given in perceptual awareness. Second, on the semirealist’s view of particulars it becomes difficult to defend an epistemological version of scientific realism according to which we have good reasons to believe that the same things are referred to despite the fact that successive theories may attribute different properties to them.
This paper proposes a reconstruction of 1913 Bohr’s theory of the hydrogen atom in the framework ... more This paper proposes a reconstruction of 1913 Bohr’s theory of the hydrogen atom in the framework of the model-theoretic approach of theories. On the basis of this reconstruction, it is argued that Bohr’s theory is not internally inconsistent and can’t be qualified as fictitious. Then, a selective realist interpretation of Bohr’s theory can be defended according to which electrons occupy energy levels. An agnostic attitude however is recommended as far as the electron’s trajectories are concerned.
A scientific mathematical law is causal if and only if it is a process law that contains a time d... more A scientific mathematical law is causal if and only if it is a process law that contains a time derivative. This is the intrinsic criterion for causal laws we propose. A process is a space-time line along which some properties are conserved or vary. A process law contains a time variable, but only process laws that contain a time derivative are causal laws. An effect is identified with what corresponds to a time derivative of some property or magnitude in a process law, whereas the other terms correspond to the cause(s). According to our criterion, causes are simultaneous with their effects and causality has no temporal direction. Several examples from natural and social disciplines support the applicability of our criterion to all scientific laws. Various objections to our proposal are presented and refuted. The merits our intrinsic theory of causality vis-à-vis the Salmon-Dowe conserved quantity theory are discussed.
After a brief presentation of what I believe to be the main features of the modelling demarche i... more After a brief presentation of what I believe to be the main features of the modelling demarche in science, I will focus on the basic following question: how can an abstract entity – a model – possibly represent an existing observable entity, which is phenomenally accessible to us, but which is not abstract? This is what Bas van Fraassen calls “the loss of reality objection.” Instead of proposing a pragmatic dissolution of this objection as van Fraassen does, I will argue that scientific representing necessarily involves a homomorphism between structures and thus that, in a strict technical sense of representation, phenomena are not represented by our models but only as having some specific properties belonging to the domains of our representing structures. Yet, our contact with phenomenal entities is secured by propositions that are true in a correspondence sense. The truth of these – ontic – propositions which state that that phenomenal entities possess some precise properties are the soil on which the informative content of our successful representations rest.
This paper is devoted to an analysis of some aspects of Bas van Fraassen's views on representatio... more This paper is devoted to an analysis of some aspects of Bas van Fraassen's views on representation. While I agree with most of his claims, I disagree on the following three issues. Firstly, I contend that some isomorphism (or at least homomorphism) between the representor and what is represented is a universal necessary condition for the success of any representation, even in the case of misrepresentation. Secondly, I argue that the so-called "semantic" or "model-theoretic" construal of theories does not give proper due to the role played by true propositions in successful representing practices. Thirdly, I attempt to show that the force of van Fraassen's pragmatic -and antirealist -"dissolution" of the "loss of reality objection" loses its bite when we realize that our cognitive contact with real phenomena is achieved not by representing but by expressing true propositions about them.
After a brief presentation of what I take to be the representational démarche in science, I stres... more After a brief presentation of what I take to be the representational démarche in science, I stress the fundamental role of true judgements in model construction. The success and correctness of a representation rests on the truth of judgements which attribute properties to real targeted entities, called "ontic judgements". I then present what van Fraassen calls "the Loss of Reality objection". After criticizing his dissolution of the objection, I offer an alternative way of answering the Loss of Reality objection by showing that the contact of our models with reality is grounded on the truth of ontic judgements. I conclude by examining the consequence of this view on the issue of scientific realism.
A representation is always a purported representation of something. Thus, it presupposes a repres... more A representation is always a purported representation of something. Thus, it presupposes a representor and a represented. Two main problems arise here. First, how can the representor represent what is represented? Second, since we are immediately only acquainted with ‘observable phenomena’ what reasons have we to believe that a representor correctly hits on something real? In his latest book Scientific representation: Paradoxes of Perspective Bas van Fraassen does not rest satisfied with the merit of addressing these daunting - yet central - philosophical problems head-on, but he also offers exciting and carefully argued solutions to them. To tackle the first problem, van Fraassen takes his clue from art and the notion of perspective which he submits to detailed scrutiny. He then contends that the second problem is dissolved by resorting to pragmatics. Although I am by in large sympathetic with van Fraassen’s views on representation, I am more reluctant to embrace his proposed pragmatic dissolution which, as far as I understand, depends upon the acceptance of what Michel Foucault appropriately called the épistèmè de la representation. As I see it, the major philosophical challenge here is to free ourselves from the view that knowing is representing, a view that opens an unbridgeable chasm between our representations and things.
La loi des chocs occupe une place importante dans la physique cartésienne. Pour
Descartes en effe... more La loi des chocs occupe une place importante dans la physique cartésienne. Pour Descartes en effet, tous les changements dans la nature résultent en définitive de collisions, et de collisions seulement. Mais si la loi des chocs - et les sept règles qui la suivent dans les Principes de la philosophie2 - sont claires en elles-mêmes, l’argumentation développée par Descartes en leur faveur continue de susciter la perplexité des commentateurs. Je tenterai, en m’inspirant principalement des travaux de Gabbey (1980) et Garber (1999), de dégager les principes sur lesquels reposent les sept règles déterministes des chocs. Je montrerai que ces sept règles peuvent être déduites de trois conditions. J’examinerai ensuite les fondements dynamiques de ces trois conditions et de la théorie cartésienne des chocs pour en relever les difficultés.
A b s tr a c t P rinc ip ia, 1 1 ( 2 ) ( 2 0 0 7 ) , p p . 12 7 -4 9 . P u b lish e d b y N E L -... more A b s tr a c t P rinc ip ia, 1 1 ( 2 ) ( 2 0 0 7 ) , p p . 12 7 -4 9 . P u b lish e d b y N E L -E p iste m o lo g y a n d L o g ic R e se a rc h Gro u p , F e d e ra l U n iv e rsity o f S a n ta C a ta rin a ( U F S C ) , B ra z il.
UMA DEFESA INDUTIVISTA BOTTOM-UP DO REALISMO CIENTÍFICO EPISTEMOLÓGICO, 2023
Neste artigo, apresento uma defesa do realismo científico epistemológico, segundo a qual temos ma... more Neste artigo, apresento uma defesa do realismo científico epistemológico, segundo a qual temos mais razões para acreditar na realidade das entidades detectadas e na verdade aproximada das proposições sobre elas. Minha defesa é diferente das estratégias explicativas usuais. Em vez de desenvolver uma argumentação explicativa top-down, que consiste em avaliar os méritos de várias explicações de fenômenos e, em seguida, decretar que a melhor explicação provavelmente será verdadeira, oferecerei um argumento bottom-up que parte de observações para ascender às causas que as produzem. Embora essas causas não sejam diretamente observadas, temos boas razões para acreditar em sua existência se forem detectadas, ou seja, se estiverem causalmente ligadas a observações diretas. Essa abordagem bottom-up tem a vantagem de não ser vulnerável às objeções levantadas contra a inferência da melhor explicação. Para ilustrar esse ponto, argumentarei que o famoso argumento de Le Verrier para a existência de Netuno é convincente precisamente porque implementa essa estratégia bottom-up.
Mechanistic Explanations in Physics and Beyond, 2019
The present paper critically examines the main claims of the new mechanist account of explanation... more The present paper critically examines the main claims of the new mechanist account of explanation defended by Glennan and Machamer, among others. The two major difficulties of the new mechanism, namely the circularity objection and the bottoming out problem are discussed and addressed. To solve the bottoming out problem, this paper proposes a modification and enlargement of the mechanist account of explanation advocated by Salmon and Dowe. Such extension can then successfully apply to the explanations provided for the global behaviour of complex systems, not only in physics but also in other disciplines such as biology and the social sciences. The proposed enlarged version of Salmon’s and Dowe’s account provides a monistic account of explanation based on causal generalizations or laws which need not be construed as necessary to fulfil their explanatory role. Such change-relating generalizations or laws are characterized by the presence of a term that refers to the variation in time of some property, which is identified to the effect whereas the other terms refer to the causes. Thus, by enlarging the Salmon and Dowe notion of mechanism, I advocate a nomological theory of causation instead of the mechanistic theory of causation proposed by Glennan et alii.
Book review published in Metascience online October 2017 of Jean Bricmont's
Making sense of qua... more Book review published in Metascience online October 2017 of Jean Bricmont's
Explanationist strategies for defending epistemological scientific realism (ESR) make heavy use o... more Explanationist strategies for defending epistemological scientific realism (ESR) make heavy use of a particular version of inference to the best explanation (IBE) known as the no-miracle argument (NMA). I consider ESR to be a genuinely philosophical-non-naturalistic – thesis which contends that there are strong arguments to believe in some non-observational claims made by scientific theories that are partially predictively correct. In this paper, I examine the grounds of the strength of these arguments from what I call a contemplative perspective which focuses on the end products, i.e. theories, of the scientific activity as opposed to the pragmatist view which considers science to be primarily an activity. I briefly rehearse the main difficulties of the no-miracle argument and of inference to the best explanation in general. I argue that a convincing defence of ESR should be based on the empirically ascertained reality of causal connections between theoretical entities which possess properties that are in principle observable (OP properties) and the results of measurements or observations. The knowledge of those causal connections may well deliver an – even the best – explanation of the appearances. But belief in the existence of some unobservable entities is mainly justified by their empirically attested causal role, not on their possible explanatory function.
In this paper I advocate a version of selective epistemological realism. I begin with analyzing t... more In this paper I advocate a version of selective epistemological realism. I begin with analyzing the conditions in which a scientific model successfully and correctly represents an identified target. I stress that the realistic import of models rests on the truth of some predicative statements. I then examine the notions of objectivity and truth in order to be able to assess the reasons to believe in the existence of some unobserved objects posited by our best scientific theories and in the truth of some assertions about the properties that these objects possess. I distinguish between the properties that are observable in principle by means of instruments which enhance our perceptive capacities (the OP properties) and the properties that are beyond any possible observation by us, namely the properties which are purely theoretical (the PT properties), such as charm and strangeness in elementary particle physics. The OP properties are identical or similar to the observed properties of ordinary perceived things, such as velocity, volume and, admittedly more controversially, charge and mass. I propose four stringent requirements for rationally believing that an unobserved object posited by a theory possesses a specific property. Firstly, this property must be an OP property. Secondly, it must be measurable. Thirdly, it must play a causal role in producing the observed data. Fourthly, distinct independent methods for measuring this property must deliver concordant results. I then show that the generality and acceptability of these four criteria is grounded on a parallelism with the reasons we adduce for (rightly) believing in the existence of ordinary observable things which we don’t immediately perceive such as mice, in some circumstances. However, an agnostic attitude is to be recommended with respect to the possession of PT properties by an object posited by an - even successful - scientific theory.
In his Scientific Representation. Paradoxes of Perspective (2008), Bas van Fraassen offers a prag... more In his Scientific Representation. Paradoxes of Perspective (2008), Bas van Fraassen offers a pragmatic account of scientific representation and representation tout court. In this paper I examine the three conditions for a user to succeed in representing a target in some context: identification of the target of the representational action, representing the target as such and such and correctly representing it in some respects. I argue that success on these three counts relies on the supposed truth of some predicative assertions, and thus that truth is more fundamental than representation. I do this in the framework of a version of the so-called " structural " account of representation according to which the establishment of a homomorphism by the user between a structure abstracted from the intended target and some relevant structure of the representing artefact is a necessary (although certainly not sufficient) condition of success for representing the target in some respects. Finally, on the basis of a correspondence view (not theory) of truth, I show that it is possible to address what van Fraassen calls " the loss of reality objection ". In his book Scientific Representation. Paradoxes of Perspective (2008) Bas van Fraassen offers a philosophical analysis of representation which is both empiricist and pragmatic. To represent is to perform some kind of action, and actions are evaluated with respect to their success or failure in attaining specific goals. Moreover, in science success or failure in representing a target must be assessed on the basis of observable phenomena. As is well known, according to van Fraassen, science aims at empirical adequacy, that is, at saving the phenomena. Thus, a scientific theory is successful if we have good reasons to believe that it saves the phenomena within its domain. Since for van Fraassen scientific theories are models in the first place, a theory is successful if its empirical parts, called " empirical substructures " , adequately represent the phenomena within its domain. A satisfactory account of representation is thus central to van Fraassen's philosophy of science. The success of a representational action can be evaluated on three counts. First, the user of a representing artefact must succeed in identifying its target or referent. Second, the target is always represented from a certain perspective as having such and such properties. Third, we may ask if our representing activity conveys some reliable information about its target or, in other words, if our representing artefact (a scientific model for example) is adequate or accurate to its target in some respects.
In this important book, which is the outcome of several decades of intense philosophical activity... more In this important book, which is the outcome of several decades of intense philosophical activity, Evandro Agazzi offers a rigorous argumentation in favour of an original conception of scientific realism and objectivity in science. The book begins with an analysis of the origin of what the author calls “dualism” – both in its ontological and epistemological versions (29) – in which he correctly locates the source of contemporary relativist and antirealist views on science. Ontological dualism goes back to the ancient Greeks and divides the world into “surface appearances” and “deep authentic realities”. In its epistemological version, dualism appears with the birth of modern science in the 17th century. Epistemological dualism postulates a dichotomy between our ideas or mental representations, which are supposedly immediately known to us, and reality itself. Such division raises the question of the faithfulness of our representations to the realities which they are meant to represent (245). But this problem has no satisfactory solution. Once a wedge is driven between ideas and things, we are inevitably drawn to a sceptical attitude with respect to science’s capacity to reach knowledge of reality. By embracing a realist position, Agazzi stands against dualism: science aims at knowing what is real, including some unobservable entities, and manages to do so, albeit only partially.
1. The problem of identii cation and the problem of inference A main issue in the literature on l... more 1. The problem of identii cation and the problem of inference A main issue in the literature on laws is to dee ne criteria which would permit to distinguish genuine lawlike propositions from universally true propositions which describe merely accidental or fortuitous regularities in the world, such as all gold objects have a mass inferior to fty tons, to reformulate a well-known example due to Hans Reichenbach. This is the epistemological problem of identii cation. The challenge here is to formulate criteria, in the sense of suff cient conditions at least, which would justify attributing the title of law to a universally true proposition. If those criteria are satiss ed by the proposition, then we know that it is a law and that it does not just happen to be accidentally true. This is the task that Humean regularists set to themselves. Since, for them, lawlike propositions describe worldly regularities, their aim is to nd criteria which are consistent with their empiricist position and to refrain from introducing ingredients which would go beyond the realm of what is empirically accessible. In other words, serious empiricists are required to shun any kind of metaphysics. As we will see such endeavor is fraught with all sorts of diff culties. On this I agree with van Fraassen who is, in his own words, a " immoderate empiricist " (2000, 1660) and consistently sustains that there are no laws, in the sense that the search for empirically satisfactory criteria which would divide regularities into two distinct classes, lawful and unlawful, is bound to fail. Simply because there is no empirical fact, that is, some empirically detectable special kind of regularities, which would legitimate endowing the propositions which describe them with the title of law. Surely, some regularities are more general than others, but they all are regularities in the rst place and no empirical feature is available which would permit to single out some regularities and endow them with some privileged status. This is why the empiricists who would like to retain the distinction between laws and non-laws, just as scientists do, attempted to devise criteria which are internal to
After a presentation of some relevant aspects of Anjan Chakravartty’s semirealism (2007), this pa... more After a presentation of some relevant aspects of Anjan Chakravartty’s semirealism (2007), this paper addresses two difficulties that appear to be inherent to important components of his proposed metaphysics for scientific realism. First, if particulars and laws are concrete structures, namely actual groupings of causal properties as the semirealist contends, the relation between particulars and laws becomes also a relation between particulars with some annoying consequences. This worry – and some others - are resolved if laws are taken to be statements and particulars are construed not only as groupings of properties, but things that contain a non-conceptual ingredient which can be given in perceptual awareness. Second, on the semirealist’s view of particulars it becomes difficult to defend an epistemological version of scientific realism according to which we have good reasons to believe that the same things are referred to despite the fact that successive theories may attribute different properties to them.
This paper proposes a reconstruction of 1913 Bohr’s theory of the hydrogen atom in the framework ... more This paper proposes a reconstruction of 1913 Bohr’s theory of the hydrogen atom in the framework of the model-theoretic approach of theories. On the basis of this reconstruction, it is argued that Bohr’s theory is not internally inconsistent and can’t be qualified as fictitious. Then, a selective realist interpretation of Bohr’s theory can be defended according to which electrons occupy energy levels. An agnostic attitude however is recommended as far as the electron’s trajectories are concerned.
A scientific mathematical law is causal if and only if it is a process law that contains a time d... more A scientific mathematical law is causal if and only if it is a process law that contains a time derivative. This is the intrinsic criterion for causal laws we propose. A process is a space-time line along which some properties are conserved or vary. A process law contains a time variable, but only process laws that contain a time derivative are causal laws. An effect is identified with what corresponds to a time derivative of some property or magnitude in a process law, whereas the other terms correspond to the cause(s). According to our criterion, causes are simultaneous with their effects and causality has no temporal direction. Several examples from natural and social disciplines support the applicability of our criterion to all scientific laws. Various objections to our proposal are presented and refuted. The merits our intrinsic theory of causality vis-à-vis the Salmon-Dowe conserved quantity theory are discussed.
After a brief presentation of what I believe to be the main features of the modelling demarche i... more After a brief presentation of what I believe to be the main features of the modelling demarche in science, I will focus on the basic following question: how can an abstract entity – a model – possibly represent an existing observable entity, which is phenomenally accessible to us, but which is not abstract? This is what Bas van Fraassen calls “the loss of reality objection.” Instead of proposing a pragmatic dissolution of this objection as van Fraassen does, I will argue that scientific representing necessarily involves a homomorphism between structures and thus that, in a strict technical sense of representation, phenomena are not represented by our models but only as having some specific properties belonging to the domains of our representing structures. Yet, our contact with phenomenal entities is secured by propositions that are true in a correspondence sense. The truth of these – ontic – propositions which state that that phenomenal entities possess some precise properties are the soil on which the informative content of our successful representations rest.
This paper is devoted to an analysis of some aspects of Bas van Fraassen's views on representatio... more This paper is devoted to an analysis of some aspects of Bas van Fraassen's views on representation. While I agree with most of his claims, I disagree on the following three issues. Firstly, I contend that some isomorphism (or at least homomorphism) between the representor and what is represented is a universal necessary condition for the success of any representation, even in the case of misrepresentation. Secondly, I argue that the so-called "semantic" or "model-theoretic" construal of theories does not give proper due to the role played by true propositions in successful representing practices. Thirdly, I attempt to show that the force of van Fraassen's pragmatic -and antirealist -"dissolution" of the "loss of reality objection" loses its bite when we realize that our cognitive contact with real phenomena is achieved not by representing but by expressing true propositions about them.
After a brief presentation of what I take to be the representational démarche in science, I stres... more After a brief presentation of what I take to be the representational démarche in science, I stress the fundamental role of true judgements in model construction. The success and correctness of a representation rests on the truth of judgements which attribute properties to real targeted entities, called "ontic judgements". I then present what van Fraassen calls "the Loss of Reality objection". After criticizing his dissolution of the objection, I offer an alternative way of answering the Loss of Reality objection by showing that the contact of our models with reality is grounded on the truth of ontic judgements. I conclude by examining the consequence of this view on the issue of scientific realism.
A representation is always a purported representation of something. Thus, it presupposes a repres... more A representation is always a purported representation of something. Thus, it presupposes a representor and a represented. Two main problems arise here. First, how can the representor represent what is represented? Second, since we are immediately only acquainted with ‘observable phenomena’ what reasons have we to believe that a representor correctly hits on something real? In his latest book Scientific representation: Paradoxes of Perspective Bas van Fraassen does not rest satisfied with the merit of addressing these daunting - yet central - philosophical problems head-on, but he also offers exciting and carefully argued solutions to them. To tackle the first problem, van Fraassen takes his clue from art and the notion of perspective which he submits to detailed scrutiny. He then contends that the second problem is dissolved by resorting to pragmatics. Although I am by in large sympathetic with van Fraassen’s views on representation, I am more reluctant to embrace his proposed pragmatic dissolution which, as far as I understand, depends upon the acceptance of what Michel Foucault appropriately called the épistèmè de la representation. As I see it, the major philosophical challenge here is to free ourselves from the view that knowing is representing, a view that opens an unbridgeable chasm between our representations and things.
La loi des chocs occupe une place importante dans la physique cartésienne. Pour
Descartes en effe... more La loi des chocs occupe une place importante dans la physique cartésienne. Pour Descartes en effet, tous les changements dans la nature résultent en définitive de collisions, et de collisions seulement. Mais si la loi des chocs - et les sept règles qui la suivent dans les Principes de la philosophie2 - sont claires en elles-mêmes, l’argumentation développée par Descartes en leur faveur continue de susciter la perplexité des commentateurs. Je tenterai, en m’inspirant principalement des travaux de Gabbey (1980) et Garber (1999), de dégager les principes sur lesquels reposent les sept règles déterministes des chocs. Je montrerai que ces sept règles peuvent être déduites de trois conditions. J’examinerai ensuite les fondements dynamiques de ces trois conditions et de la théorie cartésienne des chocs pour en relever les difficultés.
A b s tr a c t P rinc ip ia, 1 1 ( 2 ) ( 2 0 0 7 ) , p p . 12 7 -4 9 . P u b lish e d b y N E L -... more A b s tr a c t P rinc ip ia, 1 1 ( 2 ) ( 2 0 0 7 ) , p p . 12 7 -4 9 . P u b lish e d b y N E L -E p iste m o lo g y a n d L o g ic R e se a rc h Gro u p , F e d e ra l U n iv e rsity o f S a n ta C a ta rin a ( U F S C ) , B ra z il.
Em que medida uma teoria científica pode
ser considerada verdadeira? Vários debates atuais da fil... more Em que medida uma teoria científica pode ser considerada verdadeira? Vários debates atuais da filosofia da ciência convergem para essa questão. Trata-se, primeiramente, de uma questão epistemológica, pois diz respeito ao alcance e aos limites do conhecimento científico. Todavia, é também uma questão metafísica, visto que nos impõe uma interrogação sobre a natureza das entidades postuladas pelas teorias científicas. No presente livro, o leitor terá oportunidade de se informar e refletir sobre uma concepção realista acerca das teorias científicas. Ser realista, aqui, significa acreditar que as leis científicas são – ao menos parcial e aproximativamente – verdadeiras e que os modelos teóricos também representam estruturas inacessíveis à percepção sensível imediata. No âmbito dessa perspectiva realista, o autor discute e critica as concepções das leis científicas propostas pelos neorregularistas inspirados em Hume, de um lado, e pelos chamados necessitaristas categorialistas, tais como Armstrong, Dretske e Tooley, de outro lado. Em contrapartida a esses modos de pensar, o autor oferece uma concepção baseada numa metafísica neoaristotélica da natureza. Buscar as razões para aceitar a existência de poderes causais ou disposições aos quais se possa atribuir os fundamentos metafísicos das regularidades encontradas na natureza e, ao mesmo tempo, da verdade de proposições contrafactuais – eis o desafio a que se propôs o autor e que lhe serve como inspiração e ocasião para apresentar a seu leitor as questões centrais da filosofia da ciência neste início do séc. XXI.
Back in 1964, Richard Feynman famously stated that « Nobody understands quantum mechanics. » Inde... more Back in 1964, Richard Feynman famously stated that « Nobody understands quantum mechanics. » Indeed, despite its impressive empirical success, quantum mechanics (QM) remains the most perplexing and mind boggling theory ever produced by humans. In his clear and thought provoking book, Jean Bricmont advocates the merits of " the de Broglie-Bohm theory " and forcefully argues that it provides an intelligible picture of the quantum world out there. Being aware however that the de Broglie-Bohm theory is not immune of difficulties, the author acknowledges that understanding QM is an " unfinished story " (292). After a short introductory chapter, Bricmont discusses in chapter 2 what he calls the " first mystery " of quantum mechanics, namely " interference and superpositions ". Spin measurements with Mach-Zehnder interferometers (§ 2.2) show that the quantum state is a superposition of two incompatible states (spin up and spin down). When a measurement is performed, the quantum state instantly collapses into one of the two states. Schrödinger's celebrated cat thought experiment (38) was meant to show that believing in the existence of a superposition of states " cat alive " and " cat dead " before opening the box, simply is absurd. According to standard QM the evolution of the quantum state is described by solutions of the deterministic Schrödinger's equation, but the collapse is non-deterministic and occurs with a probability whose value is determined (Born's rule) by the state function Ψ. The assumption that particles would possess a spin value independently of the interaction with the measuring apparatus is blocked by " no-hidden variables theorems " (43). However, this doesn't force us to embrace some form of idealism according to which a human observer would cause the collapse since the interaction between the quantum state and the apparatus is an objective fact. Nor do the no-hidden variable theorems preclude that an individual
Dans cet important ouvrage, fruit de plusieurs dizaines d'années de réflexion, Evandro Agazzi pré... more Dans cet important ouvrage, fruit de plusieurs dizaines d'années de réflexion, Evandro Agazzi présente une argumentation rigoureuse en faveur d'une conception originale de réalisme scientifique et de l'objectivité dans les sciences. Le livre s'ouvre par une analyse historique des origines de ce que l'auteur appelle le dualisme, aussi bien ontologique qu'épistémologique (29), dans lequel il voit à juste titre l'origine des courants antiréalistes et relativistes contemporains. Sur le plan ontologique, ce dualisme remonte à l'antiquité grecque et divise le réel entre les « apparences de surface » et les « réalités profondes, authentiques ». Le dualisme épistémologique prend naissance au 17 ème siècle en même temps que la science moderne et opère une dichotomie entre ce que nous supposons immédiatement connaissable, à savoir nos idées ou représentations mentales, et la réalité en elle-même. Se pose alors la question de la fidélité de nos représentations avec les réalités censées les représenter (245), une question mal posée à laquelle il est impossible de bien répondre. En creusant un fossé infranchissable entre nos idées et les choses, un tel dualisme débouche inévitablement sur une attitude sceptique quant à la capacité de la science d'atteindre le réel. En adoptant une position réaliste, Agazzi s'oppose au dualisme : la science vise la connaissance du réel tel qu'il est, y compris de certaines réalités inobservables, et elle y parvient, quoique de façon partielle.
Diego Marconi Il mestiere di pensare. La filosofia nell'epoca del professionismo. Torino : Giulio... more Diego Marconi Il mestiere di pensare. La filosofia nell'epoca del professionismo. Torino : Giulio Einaudi editore. 2014. 154p. 10,5x18cm. 11€ Quel philosophe professionnel, qu'il soit chercheur ou professeur, ne s'est pas vu fréquemment, et parfois avec insistance, interpellé sur les questions suivantes : pourquoi la philosophie est-elle en général si incompréhensible alors qu'elle touche aux questions essentielles à tout être humain ? Ou bien : au fond, étant donné l'absence d'accord et de progrès en philosophie, les sciences ne sont-elles pas les seules capables de fournir des réponses fiables aux questions que se pose l'humanité ? Ou encore : n'est-ce pas parce que la philosophie pratiquée dans les Universités est devenue si spécialisée et technique qu'elle a perdu tant d'influence dans la culture contemporaine ?
Uploads
Papers by Michel Ghins
Making sense of quantum dynamics
I propose four stringent requirements for rationally believing that an unobserved object posited by a theory possesses a specific property. Firstly, this property must be an OP property. Secondly, it must be measurable. Thirdly, it must play a causal role in producing the observed data. Fourthly, distinct independent methods for measuring this property must deliver concordant results. I then show that the generality and acceptability of these four criteria is grounded on a parallelism with the reasons we adduce for (rightly) believing in the existence of ordinary observable things which we don’t immediately perceive such as mice, in some circumstances. However, an agnostic attitude is to be recommended with respect to the possession of PT properties by an object posited by an - even successful - scientific theory.
The book begins with an analysis of the origin of what the author calls “dualism” – both in its ontological and epistemological versions (29) – in which he correctly locates the source of contemporary relativist and antirealist views on science. Ontological dualism goes back to the ancient Greeks and divides the world into “surface appearances” and “deep authentic realities”. In its epistemological version, dualism appears with the birth of modern science in the 17th century. Epistemological dualism postulates a dichotomy between our ideas or mental representations, which are supposedly immediately known to us, and reality itself. Such division raises the question of the faithfulness of our representations to the realities which they are meant to represent (245). But this problem has no satisfactory solution. Once a wedge is driven between ideas and things, we are inevitably drawn to a sceptical attitude with respect to science’s capacity to reach knowledge of reality.
By embracing a realist position, Agazzi stands against dualism: science aims at knowing what is real, including some unobservable entities, and manages to do so, albeit only partially.
Descartes en effet, tous les changements dans la nature résultent en définitive
de collisions, et de collisions seulement. Mais si la loi des chocs - et les
sept règles qui la suivent dans les Principes de la philosophie2 - sont claires
en elles-mêmes, l’argumentation développée par Descartes en leur faveur continue
de susciter la perplexité des commentateurs. Je tenterai, en m’inspirant
principalement des travaux de Gabbey (1980) et Garber (1999), de dégager les
principes sur lesquels reposent les sept règles déterministes des chocs. Je
montrerai que ces sept règles peuvent être déduites de trois conditions.
J’examinerai ensuite les fondements dynamiques de ces trois conditions et de la
théorie cartésienne des chocs pour en relever les difficultés.
Making sense of quantum dynamics
I propose four stringent requirements for rationally believing that an unobserved object posited by a theory possesses a specific property. Firstly, this property must be an OP property. Secondly, it must be measurable. Thirdly, it must play a causal role in producing the observed data. Fourthly, distinct independent methods for measuring this property must deliver concordant results. I then show that the generality and acceptability of these four criteria is grounded on a parallelism with the reasons we adduce for (rightly) believing in the existence of ordinary observable things which we don’t immediately perceive such as mice, in some circumstances. However, an agnostic attitude is to be recommended with respect to the possession of PT properties by an object posited by an - even successful - scientific theory.
The book begins with an analysis of the origin of what the author calls “dualism” – both in its ontological and epistemological versions (29) – in which he correctly locates the source of contemporary relativist and antirealist views on science. Ontological dualism goes back to the ancient Greeks and divides the world into “surface appearances” and “deep authentic realities”. In its epistemological version, dualism appears with the birth of modern science in the 17th century. Epistemological dualism postulates a dichotomy between our ideas or mental representations, which are supposedly immediately known to us, and reality itself. Such division raises the question of the faithfulness of our representations to the realities which they are meant to represent (245). But this problem has no satisfactory solution. Once a wedge is driven between ideas and things, we are inevitably drawn to a sceptical attitude with respect to science’s capacity to reach knowledge of reality.
By embracing a realist position, Agazzi stands against dualism: science aims at knowing what is real, including some unobservable entities, and manages to do so, albeit only partially.
Descartes en effet, tous les changements dans la nature résultent en définitive
de collisions, et de collisions seulement. Mais si la loi des chocs - et les
sept règles qui la suivent dans les Principes de la philosophie2 - sont claires
en elles-mêmes, l’argumentation développée par Descartes en leur faveur continue
de susciter la perplexité des commentateurs. Je tenterai, en m’inspirant
principalement des travaux de Gabbey (1980) et Garber (1999), de dégager les
principes sur lesquels reposent les sept règles déterministes des chocs. Je
montrerai que ces sept règles peuvent être déduites de trois conditions.
J’examinerai ensuite les fondements dynamiques de ces trois conditions et de la
théorie cartésienne des chocs pour en relever les difficultés.
ser considerada verdadeira? Vários debates atuais da filosofia
da ciência convergem para essa questão. Trata-se, primeiramente,
de uma questão epistemológica, pois diz respeito ao
alcance e aos limites do conhecimento científico. Todavia, é
também uma questão metafísica, visto que nos impõe uma
interrogação sobre a natureza das entidades postuladas pelas
teorias científicas. No presente livro, o leitor terá oportunidade
de se informar e refletir sobre uma concepção realista
acerca das teorias científicas. Ser realista, aqui, significa
acreditar que as leis científicas são – ao menos parcial e
aproximativamente – verdadeiras e que os modelos teóricos
também representam estruturas inacessíveis à percepção
sensível imediata. No âmbito dessa perspectiva realista, o
autor discute e critica as concepções das leis científicas
propostas pelos neorregularistas inspirados em Hume, de um
lado, e pelos chamados necessitaristas categorialistas, tais
como Armstrong, Dretske e Tooley, de outro lado. Em contrapartida
a esses modos de pensar, o autor oferece uma concepção
baseada numa metafísica neoaristotélica da
natureza. Buscar as razões para aceitar a existência
de poderes causais ou disposições aos quais se
possa atribuir os fundamentos metafísicos das
regularidades encontradas na natureza e, ao
mesmo tempo, da verdade de proposições
contrafactuais – eis o desafio a que se propôs o
autor e que lhe serve como inspiração e ocasião
para apresentar a seu leitor as questões centrais
da filosofia da ciência neste início do séc. XXI.