Abstracts of presentations

Jean-Pascal Anfray (Ecole Normale Supérieure, Paris)

How relevant is modal ontology to modal epistemology? Descartes on Objective possibility, Essences and the Creation of Eternal Truths

As is well known, Descartes regularly uses conceivability as a guide to possibility. More precisely, the conceivability of p, narrowly understood as the clear and distinct perception of p as possible, guarantees that p is "really" possible. The doctrine of the creation of eternal truths (Creation Doctrine or CD for short) raises difficulties with the conceivability-possibility move. In the literature, interpreters tend to focus on the consequences of CD for Descartes’s conception of modality, but rarely address the question of the ontological status of eternal truths. In this paper, I will examine the relevance of the ontological status of eternal truths for both the nature of modality (i.e. whether Descartes is a modal anti-realist or as accepts modal facts of sorts) and the possibility of modal knowledge.

David Chalmers (Australian National University / New York University)

Two concepts of metaphysical possibility

I suggest that there are two concepts of metaphysical possibility: one on which possibility is prior to actuality, and one on which possibility is posterior to actuality. I apply this distinction to debates about phyicalism, haecceitism, grounding, and modal epistemology.

Bob Hale (University of Sheffield)

Knowledge of the natures of things

I shall approach the problem of modal knowledge from the standpoint of an essence-based account of necessity and possibility. Metaphysical necessities are those holds which true in virtue of the nature of things. I distinguish a priori knowledge of essence from a posteriori, offer an explanation of the former, and defend what I take to be a version of Kripke's account of the latter. This includes some discussion of essentiality of kind-membership and also of essentiality of origin (a restricted version of which I defend, while remaining somewhat agnostic about Kripke's notorious 'proof' of the general thesis, in Naming and Necessity  fn56)

Christian Nimtz (Bielefeld University)

Modal Knowledge from Conceptual Truth

I argue that there is a reliable epistemic route from the knowledge of humdrum conceptual truths we have to knowledge of metaphysical necessities. In a first step, I argue that we possess knowledge of conceptual truths since we know what (many of) our terms apply to. Besides its being widely agreed, I argue that knowledge of this kind is a prerequisite for the role our terms play in information-conveying communication. In a second step, I argue that the knowledge of conceptual truths we so possess allows us to reliably attain knowledge of metaphysical necessities. There are defeaters to (NN) “Any conceptually necessary statement is ipsofacto metaphysically necessary”; Kripke’s meter-sentence (KMS) “The standard meter is one meter long at t₀” is a case in point. But as I argue, all defeaters to NN are armchair-traceable and thus harmless. A harmful defeater to NN would have to be a strong possibility: a conceptually necessary statement that is metaphysically contingent although it is – in contrast to KMS – not actuality-dependent. I argue that there are no strong possibilities. I conclude that the conceptual knowledge we possess since we know what (many of) our terms apply to reliably yields knowledge of metaphysical necessities.  

Sonia Roca-Royes (Stirling University)

Concepts and the epistemology of essential truths

Fleeing from innateness or mysterious intuitions, rationalism in modality is mostly defended by means of a concept-based account, either of the sort of Peacocke's-which takes modal concepts to encode the essential truths-or of the sort of Chalmers'-which, instead, takes essential truths to be spread across the conceptual network. In this paper, I shall offer a diagnosis of the limits and prospects of a rationalist, concept-based epistemology of essence. I will do so by reflecting on the consequences of there being (hypothetically at least) general modally loaded concepts and also singular modally loaded concepts. I shall argue that, even if we were in possession of such concepts, the prospects of a concept-based epistemology of modality are significantly limited.

Pierre Saint-Germier (Ecole Normale Supérieure de Lyon)

What conceivability could be (and what it could imply)

Does concevability entail possibility ? Part of the problem is that we are pretty much in the dark as to what conceivability is exactly, although some interesting attempts have been made to clarify and disambiguate the notion. We give a new explication of the notion de concevability, based on Pavel Tichy's theory of constructions and Pavel Materna's theory of concepts. We then examine the prospects of a modal epistemology based on this notion of conceivability.

Scott Shalkowski (Leeds University)

The Metaphysics of Concepts and the Prospects of Modal Knowledge

The relevance of concepts to modal knowledge is partly a function of the nature of concepts. I will explore the main options regarding the nature of concepts, with an eye towards which, if any, holds any promise for accounting for any modal knowledge as conceptual knowledge.

Margot Strohminger (Arché, University of St Andrews)

Metaphysical Conceivings and Appearances of Possibility

According to one family of principles in the epistemology of (metaphysical) modality, if someone S conceives or imagines that p in a certain way—or metaphysically conceives that p—then S has prima facie justification to believe àp. Such principles preserve the spirit if not the letter of Hume’s maxim, or the view that conceivability is a guide to possibility. What is metaphysical conceiving, though? In this talk, I consider the prospects for the view that metaphysical conceiving involves an appearance of possibility.