Christopher Peacocke

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

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..

Drawing upon a conception of the metaphysics of conscious states and of first-person content, we can argue that Descartes's transition ‘Cogito ergo sum’ is both sound and one he is entitled to make. We can nevertheless formulate a version of Lichtenberg's objection that can still be raised after Bernard Williams's discussion. I argue that this form of Lichtenberg's revenge can also be undermined. In doing so it helps to compare the metaphysics of subjects, worlds and times. The arguments also apply to Descartes's ‘second Cogito’, that it is one and the same subject that thinks, wills, imagines

Among the unpublished writings of Kazimierz Twardowski so far there is an essay in which Twardowski tries to embed the concept of an intentional object' within a theory that comprises at the same time psychological, logical and grammatical aspects. This theory of actions' and products' is presented here and several applications of the theory are discussed. The central question thereby is whether the distinction between actions and products enables Twardowski to counter the objection of psychologism raised against him. Having explained Twardowski's position we describe from an editorial point of view the text in which his theory is transmitted. The text itself is published according to the given editorial principles after this introduction

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

This collection of newly commissioned essays, edited by NYU philosophers Paul Boghossian and Christopher Peacocke, resumes the current surge of interest in the proper explication of the notion of a priori. The authors discuss the relations of the a priori to the notions of definition, meaning, justification, and ontology, explore how the concept figured historically in the philosophies of Leibniz, Kant, Frege, and Wittgenstein, and address its role in the contemporary philosophies of logic, mathematics, mind, and science. The editors’ Introduction familiarizes the reader with the issues that are to be explored in detail in later parts of the anthology.

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.

The Realm of Reason develops a new, general theory of what it is for a thinker to be entitled to form a given belief. The theory locates entitlement in the nexus of relations between truth, content, and understanding. Peacocke formulates three principles of rationalism that articulate this conception. The principles imply that all entitlement has a component that is justificationally independent of experience. The resulting position is thus a form of rationalism, generalized to all kinds of content. To show how these principles are realized in specific domains, Peacocke applies the theory in detail to several classical problems of philosophy, including the nature of perceptual entitlement, induction, and the status of moral thought. These discussions involve an elaboration of the structure of entitlement in ways that have applications in many other areas of philosophy. He also relates the theory to classical and recent rationalist thought, and to current issues in the theory of meaning, reference and explanation. In the course of these discussions, he proposes a general theory of the a priori. The focus of the work lies in the intersection of epistemology, metaphysics, and the theory of meaning, and will be of interest both to students and researchers in these areas, and to anyone concerned with the idea of rationality

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.

Only computational explanations of a content‐involving sort can answer certain ‘how’‐questions; can support content‐involving counterfactuals; and have the generality characteristic of psychological explanations. Purely formal characteriza‐tions of computations have none of these properties, and do not determine content. These points apply not only to psychological explanation, but to Turing machines themselves. Computational explanations which involve content are not opposed to naturalism. They are also required if we are to explain the content‐involving properties of mental states.

A theory of understanding -- Truth's role in understanding -- Critique of justificationist and evidential accounts -- Do pragmatist views avoid this critique? -- A realistic account -- How evidence and truth are related -- Three grades of involvement of truth in theories of understanding -- Anchoring -- Next steps -- Reference and reasons -- The main thesis and its location -- Exposition and four argument-types -- Significance and consequences of the main thesis -- The first person as a case study -- Fully self-conscious thought -- Immunity to error through misidentification relative to the first person -- Can a use of the first-person concept fail to refer? -- Some conceptual roles are distinctive but not fundamental -- Implicit conceptions -- Implicit conceptions : motivation and examples -- Deflationary readings rejected -- The phenomenon of new principles -- Explanation by implicit conceptions -- Rationalist aspects -- Consequences : rationality, justification, understanding -- Transitional -- Applications to mental concepts -- Conceiving of conscious states -- Understanding and identity in other cases -- Constraints on legitimate explanations in terms of identity -- Why is the subjective case different? -- Attractions of the interlocking account -- Tacit knowledge, and externalism about the internal -- Is this the myth of the given? -- Knowledge of others' conscious states -- Communicability : between Frege and Wittgenstein -- Conclusions and significance -- 'Another I' : representing perception and action -- The core rule -- Modal status and its significance -- Comparisons -- The possession-condition and some empirical phenomena -- The model generalized -- Wider issues -- Mental action -- The distinctive features of action-awareness -- The nature and range of mental actions -- The principal hypothesis and its grounds -- The principal hypothesis : distinctions and consequences -- How do we know about our own mental actions? -- Concepts of mental actions and their epistemological significance -- Is this account open to the same objections as perceptual models of introspection? -- Characterizing and unifying schizophrenic experience -- The first person in the self-ascription of action -- Rational agency and action-awareness -- Representing thoughts -- The puzzle -- A proposal -- How the solution treats the constraints that generate the puzzle -- Relation to single-level treatments -- An application : reconciling externalism with distinctive self-knowledge.