Sciences, normes, décision - Les limites du connaissable / Limits of the knowable

Sciences, normes, décision

Accueil > Activités > Colloques et bourses > 2015

Les limites du connaissable / Limits of the knowable

par Emilio Thalabard - publié le , mis à jour le

Workshop international, 22 mai 2015, Salle Louis Liard, 9h-18h (Sorbonne)

Organisé par SND et Philo’Doctes

Organisateurs : Fabien Mikol, Jean-Baptiste Rauzy

Intervenants invités : 

- Timothy Williamson (Oxford University)
- Roy Sorensen (Washington University, Saint-Louis)
- Paul Egré (CNRS, Institut Jean-Nicod)


Intervenants sélectionnés :


- Philipp Berghofer (PhD student, University of Graz, Austria)
- Fredrik Stjernberg (Professor of Philosophy, Linkoping University, Sweden)
- Jakub Gomułka (Assistant Professor at the Chair of philosophy of God, Faculty of Philosophy, Pontifical University of John Paul II in Kraków)
Programme :

9h-9h15 - Accueil
9h15-9h30 - Présentation de la journée
9h30-10h15 - Jakub Gomułka : "McGinn’s Mysterianism Contra Meta-mysterianism"
10h15-11h - Philipp Berghofer : "Fitch’s Paradox of Knowability and the Limits of Knowledge"
11h-11h15 - Pause
11h15-12h30 - Roy Sorensen : "The Dark Side of Modesty" with a response from Julia Driver
12h30-14h30 - Déjeuner
14h30-15h15 - Fredrik Stjernberg : "Typing Knowledge and Elusive Truths"
15h15-16h30 - Paul Egré : "Knowledge and Adequate Reasons"
16h30-16h45 - Pause
16h45-18h - Timothy Williamson : "Edgington on Possible Knowledge of Unknown Truth"
18h-18h15 - Conclusion & discussion

Résumés des interventions :

Jakub Gomułka

"McGinn’s Mysterianism Contra Meta-mysterianism"

Colin McGinn developed a peculiar solution to the "hard problem" of mind which he named the “transcendental physicalism”. It is known under a name "mysterianism" since it assumes an existence of a physical theory of mind which is essentially mysterious to us. My point is that this doctrine is implausible and incoherent, however some of its basic intuitions are right. So, firstly, I will argue against McGinn’s conception from the Wittgensteinian perspective, and secondly, I will present my own idea of "meta-mysterianism". According to the latter what we really cannot know is not the correct answer to the question regarding the nature of subjectivity, but rather the correct form of the very question.

Philipp Berghofer

"Fitch’s Paradox of Knowability and the Limits of Knowledge"

Fitch’s paradox of knowability proves that, necessarily, if there is an unknown truth, then there is an unknowable truth, a truth that could not possibly be known. As we are not omniscient, we have to conclude that there are unknowable truths. I discuss the impact of Fitch’s argument on the question whether there are limits for (human) knowledge and I will show that there is no impact at all. Fitch’s argument is rightly considered a powerful argument against anti-realism, but it neither implies nor indicates that there are unanswerable questions or that it is impossible to become omniscient.

Roy Sorensen

"The Dark Side of Modesty" with a response from Julia Driver

In “The Virtues of Ignorance” Julia Driver argues that modesty is a counterexample to the Socratic equation : Virtue is Knowledge. Sherlock Holmes, loyal to the Greek aphorism “Know Thyself”, anticipates her threat : “My dear Watson," said [Sherlock Holmes], "I cannot agree with those who rank modesty among the virtues. To the logician all things should be seen exactly as they are, and to underestimate one’s self is as much a departure from truth as to exaggerate one’s own powers.” ― Arthur Conan Doyle, The Adventure of the Greek Interpreter.
 Driver defends the common sense classification of modesty as a virtue by enumerating the social benefits of under-estimating yourself. Sherlock enumerates the social costs. The ignorance entailed by blindspots is contagious. The basis of this contagion is logical rather then causal : If I underestimate myself and believe you are my equal, then my modesty commits me to underestimating you. You may rightly resent me for this underestimation both intrinsically, for my failure to recognize how much you deserve, and extrinsically, for the consequences of my underestimation. 
 In addition to my ignorance of my merit spreading to my ignorance of your merit, my ignorance can make you ignorant ! For if you and I are epistemic peers, then the limits of my knowledge become the limits of your knowledge. How do you know that I am modest rather than accurate ? If I am in just as good a position to judge my merit as you, then the fact that I disagree with your estimate is reason for you to revise your judgment.Sherlock’s conclusion : My blindspot drags you down. Your absence of a blindspot cannot pull me up. For it is impossible for me to know my blindspot but possible for you to share my ignorance of that blindspot. Our only path to convergence runs down to ignorance, not up to knowledge.

Fredrik Stjernberg

"Typing Knowledge and Elusive Truths"


Fitch’s knowability paradox appears to show that there are unknowable propositions. By some simple steps, it shows that if all truths can be known, then all truths are known. Surely not all truths are known. Hence we should revise the claim that all truths are knowable (since that claim is the most controversial step in the reasoning). So there must be unknowable propositions. There are several suggested solutions, each with its own shortcomings. I focus on the typing solution, which I think is the best way forward for those who believe that all truths are knowable. This has its own shortcomings ; in particular, I argue that it leads to making knowledge an indefinitely extensible concept, and this means that there will be a certain kind of incompleteness in our grasp of what knowledge is. Either way, there will be facts that elude our knowledge.

Paul Egré

"Knowledge and Adequate Reasons"

Is Knowledge definable as justified true belief ? I will argue that one can legitimately answer positively or negatively to this question, depending on how the notion of justification is understood. The leading idea behind this paper is to contrast two notions of justification, a notion of internal justification, and a notion of external justification, and to argue that the equation between knowledge and the notion of externally justified true belief can be sustained provided the notion of external justification is defined in terms of adequate reasons. The notion of an adequate reason raises several difficulties, however. One of them is that whether a reason is adequate or not may be not be epistemically accessible. Because of that, we may know a lot without ever being in a position to know that we know. The second concerns mixed reasons : some of our beliefs often rest on both adequate reasons and on inadequate reasons at the same time. Should those beliefs count as knowledge or not ? I will argue that one should distinguish two tasks for a knower, and two levels of knowledge with that : one is to collect adequate reasons, the other is to manage the network of one’s reasons. Knowing for certain that a reason is adequate may be very demanding or even impossible, but managing the network of one’s reasons is at least a reasonable requirement.

Timothy Williamson

"Edgington on Possible Knowledge of Unknown Truth"

The paper is a response to Dorothy Edgington’s article ‘Possible knowledge of unknown truth’ (Synthese, 2010), where she defends her diagnosis of the Church-Fitch refutation of the principle that all truths are knowable and analogous refutations of analogous principles, in response to my earlier criticisms of her diagnosis. Using counterfactual conditionals, she reformulates the knowability principle and its analogues to withstand Church-Fitch objection. In the present paper, I argue that in order to avoid a kind of trivialization, Edgington needs to supply a more general constraint on how the knower is allowed to specify a counterfactual situation for the purposes of her reformulated principles, and that it is unclear how to do so. I also question the philosophical motivation for her reformulation strategy, with special reference to her application of it to Putnam’s epistemic account of truth. In passing, I question how dangerous Church-Fitch arguments are for analogues of the knowability principle with non-factive evidential attitudes in place of knowledge. Finally, I raise a doubt about the compatibility of Edgington’s reformulation strategy with her view that counterfactual conditionals lack truth-conditions.