We argue that indeterminate probabilities are not only rationally permissible for a Bayesian agent, but they may even be rationally required . Our first argument begins by assuming a version of interpretivism: your mental state is the set of probability and utility functions that rationalize your behavioral dispositions as well as possible. This set may consist of multiple probability functions. Then according to interpretivism, this makes it the case that your credal state is indeterminate. Our second (...) argument begins with our describing a world that plausibly has indeterminate chances. Rationality requires a certain alignment of your credences with corresponding hypotheses about the chances. Thus, if you hypothesize the chances to be indeterminate, your will inherit their indeterminacy in your corresponding credences. Our third argument is motivated by a dilemma. Epistemic rationality requires you to stay open-minded about contingent matters about which your evidence has not definitively legislated. Practical rationality requires you to be able to act decisively at least sometimes. These requirements can conflict with each other-for thanks to your open-mindedness, some of your options may have undefined expected utility, and if you are choosing among them, decision theory has no advice to give you. Such an option is playing Nover and Hájek’s Pasadena Game , and indeed any option for which there is a positive probability of playing the Pasadena Game. You can serve both masters, epistemic rationality and practical rationality, with an indeterminate credence to the prospect of playing the Pasadena game. You serve epistemic rationality by making your upper probability positive-it ensures that you are open-minded. You serve practical rationality by making your lower probability 0-it provides guidance to your decision-making. No sharp credence could do both. (shrink)

The theory of personal probability needs to be developed as a logic of credibility in order to provide an adequate basis for the theories of scientific inference and rational decision making. But standard systems of personal probability impose formal structures on probability relationships which are too restrictive to qualify them as logics of credibility. Moreover, some rules for conditional probability have no justification as principles of credibility. A formal system of qualitative probability which is free (...) of these defects and which leads to a presuppositionless representation theorem is sketched. (shrink)

Part 1 Background on de Finetti’s twin criteria of coherence: Coherence1: 2-sided previsions free from dominance through a Book. Coherence2: Forecasts free from dominance under Brier (squared error) score. Part 2 IP theory based on a scoring rule.

Daniel Ellsberg presented in Ellsberg (The Quarterly Journal of Economics 75:643–669, 1961) various examples questioning the thesis that decision making under uncertainty can be reduced to decision making under risk. These examples constitute one of the main challenges to the received view on the foundations of decision theory offered by Leonard Savage in Savage (1972). Craig Fox and Amos Tversky have, nevertheless, offered an indirect defense of Savage. They provided in Fox and Tversky (1995) an explanation of Ellsberg’s two-color problem (...) in terms of a psychological effect: ambiguity aversion . The ‘comparative ignorance’ hypothesis articulates how this effect works and explains why it is important to an understanding of the typical pattern of responses associated with Ellsberg’s two-color problem. In the first part of this article we challenge Fox and Tversky’s explanation. We present first an experiment that extends Ellsberg’s two-color problem where certain predictions of the comparative ignorance hypothesis are not confirmed. In addition the hypothesis seems unable to explain how the subjects resolve trade-offs between security and expected pay-off when vagueness is present. Ellsberg offered an explanation of the typical behavior elicited by his examples in terms of these trade-offs and in section three we offer a model of Ellsberg’s trade-offs. The model takes seriously the role of imprecise probabilities in explaining Ellsberg’s phenomenon. The so-called three-color problem was also considered in Fox and Tversky (1995). We argue that Fox and Tversky’s analysis of this case breaks a symmetry with their analysis of the two-color problem. We propose a unified treatment of both problems and we present a experiment that confirms our hypothesis. (shrink)

Building on work that we reported at ISIPTA 2005 we revisit claims made by Fox and Tversky concerning their "comparative ignorance" hypothesis for decision making under uncertainty.

The notion of comparative probability defined in Bayesian subjectivist theory stems from an intuitive idea that, for a given pair of events, one event may be considered “more probable” than the other. Yet it is conceivable that there are cases where it is indeterminate as to which event is more probable, due to, e.g., lack of robust statistical information. We take that these cases involve indeterminate comparative probabilities. This paper provides a Savage-style decision-theoretic foundation for indeterminate (...) comparative probabilities. (shrink)

It has been argued recently that perception is indeterminate. But there are more than one ways of spelling out what this means. The standard line is that perceptual states attribute different probabilities to different propositions. I provide an alternative to this view, where it is not the attitude, but the content of perceptual states that is indeterminate, inasmuch as it consists of the representation of determinable properties. This view does justice to the more general claim that perception is (...) indeterminate without appealing to probability either in the attitude or in the content. (shrink)

I focus my discussion on the well-known Ellsberg paradox. I find good normative reasons for incorporating non-precise belief, as represented by sets of probabilities, in an Ellsberg decision model. This amounts to forgoing the completeness axiom of expected utility theory. Provided that probability sets are interpreted as genuinely indeterminate belief, such a model can moreover make the “Ellsberg choices” rationally permissible. Without some further element to the story, however, the model does not explain how an agent may come (...) to have unique preferences for each of the Ellsberg options. Levi holds that the extra element amounts to innocuous secondary “risk” or security considerations that are used to break ties when more than one option is rationally permissible. While I think a lexical choice rule of this kind is very plausible, I argue that it involves a greater break with xpected utility theory than mere violation of the ordering axiom. (shrink)

Pi(AS) = Pi(A)Pi(S) for i = 1, 2. But the Linear Pool created a group opinion P3 with positive dependence. P3(A|S) > P3(A).

It is commonly assumed that preferences are determinate; that is, that an agent who has a preference knows that she has the preference in question and is disposed to act upon it. This paper argues the dubiousness of that assumption. An account of indeterminate preferences in terms of self-predicting subjective probabilities is given, and a decision rule for choices involving indeterminate preferences is proposed. Wolfgang Spohn’s and Isaac Levi ’s arguments against self-predicting probabilities are also considered, in light (...) of Wlodek Rabinowicz’s recent criticism. (shrink)

Holtby, Allen and Fairchild are both recent and revolutionary decisions that address an important aspect of the indeterminate causation problem that frequently arises in tort litigation. In Holtby and Allen, the Court of Appeal departed from the traditional binary approach, under which a tort claimant either recovers compensation for his or her entire injury or is altogether denied recovery—depending on whether his or her case against the defendant is more probable than not. Holtby and Allen substituted this approach by (...) the proportionate recovery principle, under which the defendant compensates the claimant for a fraction of his or her injury that represents the defendant's statistical share in that injury. This article analyses this development within the particular domain of indeterminate causation, over which the proportionate recovery principle has been licensed to exercise control. The article claims that this development would constitute an improvement of the law from the perspectives of both optimal deterrence and corrective justice, if the courts properly formulate its scope. First, the proportionate recovery principle needs to be explicitly confined to cases that deal with recurrent wrongs. Second, determination of the defendant's share in the claimant's injury ought to be grounded on the probability of causation, rather than the risk of inflicting that injury. Third, judges must not apply unarticulated intuitions in determining the magnitude of the relevant risk or probability: their decisions in that area would be better informed by the statistical principle of ‘insufficient reason’, also known as the ‘indifference principle’. Fourth, courts are yet to relieve the doctrinal tension between the proportionate recovery principle, as recognized in Holtby and Allen, and the previous rejection of that principle by the House of Lords. Subsequently, the article analyses the House of Lords' decision in Fairchild—yet another instance of indeterminate causation in which proportionate recovery is preferable to the ‘all or nothing’ approach. In this case, the House of Lords allowed the claimants full recovery. This holding was grounded in the Law Lords' innovative approach to indeterminate causation, and the article unfolds the problematics of this approach. Finally, the article offers an adoption of yet another legal mechanism—the ‘evidential damage doctrine’—that replaces liability under uncertainty with liability for uncertainty. (shrink)

Many have claimed that unspecific evidence sometimes demands unsharp, indeterminate, imprecise, vague, or interval-valued probabilities. Against this, a variant of the diachronic Dutch Book argument shows that perfectly rational agents always have perfectly sharp probabilities.

This paper has two main parts. In the first part, we motivate a kind of indeterminate, suppositional credences by discussing the prospect for a subjective interpretation of a causal Bayesian network, an important tool for causal reasoning in artificial intelligence. A CBN consists of a causal graph and a collection of interventional probabilities. The subjective interpretation in question would take the causal graph in a CBN to represent the causal structure that is believed by an agent, and interventional probabilities (...) in a CBN to represent suppositional credences. We review a difficulty noted in the literature with such an interpretation, and suggest that a natural way to address the challenge is to go for a generalization of CBN that allows indeterminate credences. In the second part, we develop a decision-theoretic foundation for such indeterminate suppositional credences, by generalizing a theory of coherent choice functions to accommodate some form of act-state dependence. The upshot is a decision-theoretic framework that is not only rich enough to, so to speak, ground the probabilities in a subjectively interpreted causal network, but also interesting in its own right, in that it accommodates both act-state dependence and imprecise probabilities. (shrink)

Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities and recover the Born rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one (...) of the axioms of rationality used to derive the theorem, ‘branching indifference’ (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational and which violates BI. This is ‘branch counting’ (BC). Wallace is aware of BC and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. 1 Introduction2 Branching Indifference 2.1 The positive argument for branching indifference 2.2 The negative argument for branching indifference 2.3 Branching indifference section summary3 Branch Counting 3.1 Branch counting is rational under the subjective-uncertainty viewpoint 3.2 Branch counting is rational under the objective-determinism viewpoint 3.3 Branch counting section summary4 Number of Branches 4.1 Veracity of the framework 4.2 No such thing as the number of branches 4.2.1 The number of branches is indeterminate 4.2.2 The number of branches is indeterminable 4.3 Rationality and weight5 Conclusion. (shrink)

This chapter contains sections titled: The Bayesian Orthodoxy Idealization Two Approaches to a Theory of Probability Adjustment for Nonclassical Logics Carnap's Confirmation Theory Proportional Syllogisms Kyburg's Fuzzy Probabilities Levi's Indeterminate Systems Qualitative Theories of Probability The Dynamics of Subjective Probability Probability Theory and Quantum Theory.

Notions of probability and uncertainty have been increasingly prominant in modern economics. This book considers the philosophical and practical difficulties inherent in integrating these concepts into realistic economic situations. It outlines and evaluates the major developments, indicating where further work is needed. This book addresses: * probability, utility and rationality within current economic thought and practice * concepts of ignorance and indeterminancy * experimental economics * econometrics, with particular reference inference and estimation.

Bayesians often confuse insistence that probability judgment ought to be indeterminate (which is incompatible with Bayesian ideals) with recognition of the presence of imprecision in the determination or measurement of personal probabilities (which is compatible with these ideals). The confusion is discussed and illustrated by remarks in a recent essay by R. C. Jeffrey.

Orthodox Bayesian decision theory requires an agent’s beliefs representable by a real-valued function, ideally a probability function. Many theorists have argued this is too restrictive; it can be perfectly reasonable to have indeterminate degrees of belief. So doxastic states are ideally representable by a set of probability functions. One consequence of this is that the expected value of a gamble will be imprecise. This paper looks at the attempts to extend Bayesian decision theory to deal with such (...) cases, and concludes that all proposals advanced thus far have been incoherent. A more modest, but coherent, alternative is proposed. Keywords: Imprecise probabilities, Arrow’s theorem. (shrink)

The purpose of this paper is to show that if one adopts conditional probabilities as the primitive concept of probability, one must deal with the fact that even in very ordinary circumstances at least some probability values may be imprecise, and that some probability questions may fail to have numerically precise answers.

Why should we refrain from doing things that, taken collectively, are environmentally destructive, if our individual acts seem almost certain to make no difference? According to the expected consequences approach, we should refrain from doing these things because our individual acts have small risks of causing great harm, which outweigh the expected benefits of performing them. Several authors have argued convincingly that this provides a plausible account of our moral reasons to do things like vote for policies that will reduce (...) our countries’ greenhouse gas emissions, adopt plant-based diets, and otherwise reduce our individual emissions. But this approach has recently been challenged by authors like Bernward Gesang and Julia Nefsky. Gesang contends that it may be genuinely impossible for our individual emissions to make a morally relevant difference. Nefsky argues more generally that the expected consequences approach cannot adequately explain our reasons not to do things if there is no precise fact of the matter about whether their outcomes are harmful. -/- In the following chapter, author Howard Nye defends the expected consequences approach against these objections. Nye contends that Gesang has shown at most that our emissions could have metaphysically indeterministic effects that lack precise objective chances. He argues, moreover, that the expected consequences approach can draw upon existing extensions to cases of indeterminism and imprecise probabilities to deliver the result that we have the same moral reasons to reduce our emissions in Gesang’s scenario as in deterministic scenarios. Nye also shows how the expected consequences approach can draw upon these extensions to handle Nefsky’s concern about the absence of precise facts concerning whether the outcomes of certain acts are harmful. The author concludes that the expected consequences approach provides a fully adequate account of our moral reasons to take both political and personal action to reduce our ecological footprints. (shrink)

Leibniz introduit l’expression « ⁰⁄₀ » en 1672 dans un écrit mathématique sur les séries numériques pour exprimer la somme des unités. Il s’agit très probablement d’une des premières apparitions de cette expression dans l’histoire des mathématiques. Leibniz cependant l’abandonne aussitôt. Elle apparaît à nouveau dans le contexte du calcul différentiel au moment où celui-ci fait débat à l’Académie royale des sciences. Une des questions les plus saillantes soulevées par l’introduction du nouveau calcul est de savoir si la notion de (...) différentielle doit être distinguée, dans la pratique, du zéro absolu. Cet article examine les efforts effectués, dans le cadre d’une nouvelle pratique mathématique, pour donner un sens à l’expression « ⁰⁄₀ ». On verra comment cette expression cesse de représenter une impossibilité algébrique, à condition de ne plus penser « 0 » comme un zéro absolu. Désormais, elle est le signe de l’existence d’une singularité d’une courbe. L’analyse de cette construction de sens met en évidence combien la représentation diagrammatique des caractères impliqués dans le calcul était importante pour les premiers pratiquants du calcul différentiel. (shrink)

Those who model doxastic states with a set of probability functions, rather than a single function, face a pressing challenge: can they provide a plausible decision theory compatible with their view? Adam Elga and others claim that they cannot, and that the set of functions model should be rejected for this reason. This paper aims to answer this challenge. The key insight is that the set of functions model can be seen as an instance of the supervaluationist approach to (...) vagueness more generally. We can then generate our decision theory by applying the general supervaluationist semantics to decision-theoretic claims. The result: if an action is permissible according to all functions in the set, it’s determinately permissible; if impermissible according to all, determinately impermissible; and – crucially – if permissible according to some, but not all, it’s indeterminate whether it’s permissible. This proposal handles with ease some difficult cases ) on which alternative decision theories falter. One reason this view has been overlooked in the literature thus far is that all parties to the debate presuppose that an acceptable decision theory must classify each action as either permissible or impermissible. But I will argue that this thought is misguided. Seeing the set of functions model as an instance of supervaluationism provides a compelling motivation for the claim that there can be indeterminacy in the rationality of some actions. (shrink)

In this paper, we use PCR5 in order to fusion the information of two sources providing subjective probabilities of an event A to occur in the following form: chance that A occurs, indeterminate chance of occurrence of A, chance that A does not occur. -/- .

Forty years ago, Bayesian philosophers were just catching a new wave of technical innovation, ushering in an era of scoring rules, imprecise credences, and infinitesimal probabilities. Meanwhile, down the hall, Gettier’s 1963 paper [28] was shaping a literature with little obvious interest in the formal programs of Reichenbach, Hempel, and Carnap, or their successors like Jeffrey, Levi, Skyrms, van Fraassen, and Lewis. And how Bayesians might accommodate the discourses of full belief and knowledge was but a glimmer in the eye (...) of Isaac Levi. Forty years later, scoring rules, imprecise credences, and infinitesimal probabilities are all the rage. And the formal and “informal” traditions are increasingly coming together as Bayesian arguments spill over into debates about the foundations of empirical knowledge, skepticism, and more. Relatedly, Bayesian interest in full belief and knowledge has never been greater. Much more besides has happened in the last forty years of Bayesian philosophy, .. (shrink)

In this special issue, our objective is to clarify what biosemioticians may mean insofar as they claim that living systems are capable of making choices or that biosemiotic interpretations are partially indeterminate. A number of different senses of the term “chance” are discussed as we move toward a consensus. We find that biosemiosic chance may arise out of conditions involving quantum indeterminacy, randomness, deterministic chaos, or unpredictability, but biosemiosic chance is mainly due to the fact that living entities invest (...) their environments with different meanings and values, which are not inherent in the material aspects. Accordingly, interpretive responses are in part self-determined. A self-determined interpretation may be thought of as a process in which localized biases constrain the probabilities of the outcomes of the interactions between an agent and its environment. The agent’s internal formal constraints that are defined by similarity and proximity are relative and, as such, vague, and thus interpretation may be somewhat underdetermined and involve an element of chance. (shrink)

Jaynes contends that in many statistical problems a seemingly indeterminate probability distribution is made unique by the transformation group of necessarily implied invariance properties, thereby justifying the principle of indifference. To illustrate and substantiate his claims he considers Bertrand's Paradox. These assertions are here refuted and the traditional attitude is vindicated.

To handle epistemic and pragmatic risks, Gärdenfors and Sahlin (1982, 1988) design a decision procedure for cases in which probabilities are indeterminate. Their procedure steps outside the traditional expected utility framework. Must it do this? Can the traditional framework handle risk? This paper argues that it can. The key is a comprehensive interpretation of an option's possible outcomes. Taking possible outcomes more broadly than Gärdenfors and Sahlin do, expected utility can give risk its due. In particular, Good's (1952) decision (...) procedure adequately handles indeterminate probabilities and the risks they generate. (shrink)

Bayesian decision theory, in its classical or strict form, requires agents to have a determinate probability function. In recent years many decision theorists have come to think that this requirement should be weakened to allow for cases in which the agent makes indeterminate probability judgments. It has been claimed that this weakening makes the theory more realistic, and that it makes the theory more tenable as a normative ideal. This paper shows that the usual technique for weakening (...) strict Bayesianism has neither of these claimed advantages. (shrink)

Koehler's target article attempts a balanced view of the relevance of knowledge of base rates to judgments of subjective or credal probability, but he is not sensitive enough to the difference between requiring and permitting the equation of probability judgments with base rates, the interaction between precision of base rate and reference class information, and the possibility of indeterminate probability judgment.

In ‘Fair Infinite Lotteries’ (FIL), Wenmackers and Horsten use non-standard analysis to construct a family of nicely-behaved hyperrational-valued probability measures on sets of natural numbers. Each probability measure in FIL is determined by a free ultrafilter on the natural numbers: distinct free ultrafilters determine distinct probability measures. The authors reply to a worry about a consequent ‘arbitrariness’ by remarking, “A different choice of free ultrafilter produces a different ... probability function with the same standard part but (...) infinitesimal differences.” They illustrate this remark with the example of the sets of odd and even numbers. Depending on the ultrafilter, either each of these sets has probability 1/2, or the set of odd numbers has a probability infinitesimally higher than 1/2 and the set of even numbers infinitesimally lower. The point of the current paper is simply that the amount of indeterminacy is much greater than acknowledged in FIL: there are sets of natural numbers whose probability is far more indeterminate than that of the set of odd or the set of even numbers. (shrink)

Decision theory aims at a general account of rationality covering humans but to begin makes idealizations about decision problems and agents' resources and circumstances. It treats inerrant agents with unlimited cognitive power facing tractable decision problems. This book systematically rolls back idealizations and without loss of precision treats errant agents with limited cognitive abilities facing decision problems without a stable top option. It recommends choices that maximize utility using quantizations of beliefs and desires in cases where probabilities and utilities are (...) indeterminate and using higher-order utility analysis in cases of limited access to probabilities and utilities. For agents burdened with mistakes, it advocates reasonable attempts to correct unacceptable mistakes before deciding. In decision problems without a stable top option, a topic of game theory, it proposes maximizing self-conditional utility among self-supporting options. In games of strategy, the new principles lead to solutions that are Pareto optimal among equilibria composed of jointly self-supporting strategies. Offering an account of bounded rationality, the bookmakes large strides toward realism in decision theory. (shrink)

In a recent, thought-provoking paper Adam Elga argues against unsharp – e.g., indeterminate, fuzzy and unreliable – probabilities. Rationality demands sharpness, he contends, and this means that decision theories like Levi's, Gärdenfors and Sahlin's, and Kyburg's, though they employ different decision rules, face a common, and serious, problem. This article defends the rule to maximize minimum expected utility against Elga's objection.

It is natural to think of precise probabilities as being special cases of imprecise probabilities, the special case being when one’s lower and upper probabilities are equal. I argue, however, that it is better to think of the two models as representing two different aspects of our credences, which are often vague to some degree. I show that by combining the two models into one model, and understanding that model as a model of vague credence, a natural interpretation arises that (...) suggests a hypothesis concerning how we can improve the accuracy of aggregate credences. I present empirical results in support of this hypothesis. I also discuss how this modeling interpretation of imprecise probabilities bears upon a philosophical objection that has been raised against them, the so-called inductive learning problem. (shrink)

This paper discusses conditional probability $$P$$ P , or the probability of A given B. When $$P>0$$ P > 0 , the ratio formula determines $$P$$ P . When $$P=0$$ P = 0 , the ratio formula breaks down. The Borel–Kolmogorov paradox suggests that conditional probabilities in such cases are indeterminate or ill-posed. To analyze the paradox, I explore the relation between probability and intensionality. I argue that the paradox is a Frege case, similar to those (...) that arise in many probabilistic and non-probabilistic contexts. The paradox vividly illustrates how an agent’s way of representing an entity can rationally influence her credal assignments. I deploy my analysis to defend Kolmogorov’s relativistic treatment of conditional probability. (shrink)

We have earlier shown by construction that a proposition can have a welldefined nonzero probability, even if it is justified by an infinite probabilistic regress. We thought this to be an adequate rebuttal of foundationalist claims that probabilistic regresses must lead either to an indeterminate, or to a determinate but zero probability. In a comment, Frederik Herzberg has argued that our counterexamples are of a special kind, being what he calls ‘solvable’. In the present reaction we investigate (...) what Herzberg means by solvability. We discuss the advantages and disadvantages of making solvability a sine qua non , and we ventilate our misgivings about Herzberg’s suggestion that the notion of solvability might help the foundationalist. (shrink)

C'est "par ce qu'elle sous-entend ou dévoile à sa limite - par son contenu latent ou inconscient - que la phénoménologie est en consonance avec la psychanalyse", écrit Maurice Merleau-Ponty en 1960, dans la préface à l'ouvrage de Angelo Hesnard L'Oeuvre et l'esprit de Freud. Singulière euphonie, que celle ici entendue entre deux disciplines habituellement opposées dans leurs définitions : l'une centre en effet ses recherches sur la conscience, l'autre sur l'inconscient ; la première s'en tient à la description la (...) plus fidèle de ce qui apparaît, la seconde accorde le primat aux "tendances supposées" sur les "phénomènes perçus" ; celle-là radicalise le partage diltheyen des sciences de la nature et de l'esprit, et se positionne résolument du côté des secondes, celle-ci puise à la biologie ou à la thermodynamique tout autant qu'à l'herméneutique. Quelle serait donc cette harmonie entre phénoménologie et psychanalyse, dans quel système tonal se définit-elle et quelles modulations connaît l'intervalle mélodique entre les deux? Philosophie de la forme, existentialisme, phénoménologie de la perception, de l'inapparent, puis philosophie de la chair, le parcours de Merleau-Ponty semble poser, de manière à chaque fois plus fine, la question d'une paradoxale phénoménologie de l'inconscient, située à la double orée de la phénoménologie et de la psychanalyse. Il semble pertinent d'analyser ici cette traversée de la phénoménologie et de tenter de voir ce qu'elle trouve à ses confins - psychanalyse, ontologie ou métaphysique? Si la relecture merleau-pontyenne de la phénoménologie s'accompagne d'une lecture inédite de la psychanalyse, ce double remaniement ne manque pas de faire surgir bien des questions. C'est probablement là le sens des commentaires que quatre psychanalystes, J.-B. Pontalis, André Green, Jacques Lacan et Cornélius Castoriadis formulent à l'endroit de la phénoménologie de Merleau-Ponty. Ces quatre critiques soulignent la grande proximité du philosophe avec la psychanalyse, mais n'en mettent pas moins en exergue les limites d'un abord phénoménologique de l'inconscient. En effet, si la démarche de la phénoménologie consiste à aller de l'indéterminé vers plus de détermination, à instituer le sens de ce qui auparavant restait inconscient, comment appliquer cette visée à l'inconscient psychanalytique sans le réduire par là même? Que signifie alors un "inconscient" paradoxalement thématisé à partir de la perception? Cette étude propose de confronter les lectures respectives qu'effectuent Merleau-Ponty de la psychanalyse puis ces quatre psychanalystes de l'oeuvre du philosophe. Un examen des positions originales de Merleau-Ponty permet de mesurer l'incontestable rapprochement esquissé avec l'oeuvre de Freud. La réponse des psychanalystes à cet appel pointe toutefois les limites d'une lecture résolument philosophique de la psychanalyse, n'instaurant, entre les deux, qu'une cadence évitée : à l'issue de ce dialogue, nulle impression de repos, et la phrase musicale semble relancée sur d'autres lignes harmoniques. (shrink)