Christopher Peacocke

where F is a contradiction (I use his numbering). Tim says about these equivalences: (1) “modulo the implicit recognition of this equivalence, the epistemology of metaphysically modal thinking is a special case of the epistemology of counterfactual thinking. Whoever has what it takes to understand the counterfactual conditional and the elementary logical auxiliaries ~ and F has what it takes to understand possibility and necessity operators.” (158) (2) The idea that we evaluate metaphysically modal claims “by some quite different means [from those we use to evaluate counterfactuals – CP] is highly fanciful, since it indicates a bizarre lack of cognitive economy and has no plausible explanation of where the alternative cognitive resources might come from” (162) (3) “the capacity to handle metaphysical modality is an “accidental” byproduct of the cognitive mechanisms that provide our capacity to handle counterfactual conditionals” (162). The biconditional corresponding to a proposed definition of a concept C may be necessary and a priori. But that leaves open these questions: (1) Does the definition contribute to an explanation of why what are in fact truths containing C are true? (The Explanation Question) (2) Does the definition contribute to an explanation of our knowledge of certain contents containing C? (Epistemic Question) (3) Does the definition contribute to an explanation of our understanding or grasp of contents containing C? (Understanding Question) I argue that applied to (17) and (18), considered as definitions, the answers to these three..

If one were to write a book titled TheVarieties of Self-Consciousness, one would start off with some distinctions. It will help to locate my topic in relation to those distinctions.The first distinction concerns that kind of self-consciousness which involves only the minimal ability on the part of a subject to self-represent, to be in mental states with first person content, be it conceptual or nonconceptual. This minimal ability involves very little as compared with the more sophisticated states of which humans are capable. First person content can be present in the perceptual states of a creature capable of representing only some of its physical states and its relations to the physical environment, and not capable of representing anything beyond that. So the first distinction is between this minimal case, and richer varieties of self-consciousness. Some writers use ‘self-conscious’ to apply to a subject who is in any mental state involving first person content, and so they would appl

The principal thesis of A Study of Concepts is that a concept is individuated by its possession condition. Concepts are here understood to be sliced as finely as epistemic possibility. So now and 6 o’clock are different concepts, even if, in context, they pick out the same time; likewise for the observational concept circular and the complex concept locus of coplanar points equidistant from a given point. In the simplest cases, a possession condition is stated by giving a true, individuating statement of the form.

Notes on Contributors • Preface • Christopher Peacocke, Introduction: The Issues and their Further Development I OBJECTIVE THOUGHT • John Campbell, Objects and Objectivity Commentaries • Bill Brewer, Thoughts about Objects, Places and Times • John O'Keefe, Cognitive Maps, Time and Causality II OBJECTIVITY AND THE UNITY OF CONSCIOUSNESS • Susan Hurley, Unity and Objectivity Commentaries • Anthony Marcel, What is Relevant to the Unity of Consciousness? • Michael Lockwood, Issues of Unity and Objectivity III UNDERSTANDING THE MENTAL:THEORY OR SIMULATION • MARTIN DAVIES, The Mental Simulation Debate Commentaries • Jane Heal, Simulation vs. Theory Theory: What is at Issue? • Josef Perner, The Necessity and Impossibility of Simulation

It is just over fifty years since the publication of Quine’s ‘Two Dogmas of Empiricism’. That paper expresses a broad vision of the system of relations between meaning, experience, and the rational formation of belief. The deepest challenges the paper poses come not from the detailed argument of its first four sections – formidable though that is – but from the visionary material in its last two sections.1 It is this visionary material that is likely to force the reader to revise, to deepen, or to rethink her position on fundamental issues about the relations between meaning, experience, rationality, and, above all, the a priori. Does what is right in Quine’s argument exclude any rationalist view of these relations? How should a rationalist view be formulated? Those are the questions I will be addressing. I start with the critical part of this task, a consideration of the strengths and weaknesses of Quine’s vision. Drawing on the constraints emerging from that critical discussion, I will then turn to the positive task of articulating and defending a rival conception. The rival conception can be described as a Generalized Rationalism

It seems to be an obvious truth that There could be something that doesn't actually exist. That is, it seems to be obiously true that ◊∃×). It is sufficient for the truth of that there could be more people, or trees, or cars, than there actually are. It is also sufficient for the truth of that there could be some pepole, or trees, or cars that are distinct from all those that actually exist. Do and suchlike statements involve a commitment to possibilia, to things that possibly exist, but do not actually exist? If not, why not? And if so, what is the nature of the possibilia to which and its ilk commit us? These simple little questions are at the tip of an iceberg

There are issues in the theory of concepts about which A Study of Concepts could have said more. There are also some issues about which it would have done well to say something different. The commentators in this symposium have successfully identified a series of issues of one or other of these two kinds, and I am very grateful for their thought and detailed attention. I have learned from reflection on their comments, and I take this opportunity to try to carry the discussion forward by addressing a range issues underdeveloped in A Study of Concepts. Georges Rey raises global questions about the project of SoC. Answerability, Quinean challenges and the relations between my approach and covariation or ‘locking’ theories are amongst the problems he raises. The comments of David Papineau are at an intermediate level of generality. He poses questions about the subject-matter of a theory of concepts, and rejects my critique of teleological theories of content. He is also dissatisfied with my account of the relations between actual thought and the normative properties of concepts. I will consider that issue at some length. Jane Heal considers my elaboration of the approach for a specific concept, that of belief. I will take the topics in that order.