John Perry

The topic of this essay is “the slingshot,” a short argument that purports to show that sentences1 designate (stand for, refer to) truth values. Versions of this argument have been used by Frege 2, Church 3, Quine4 and Davidson5; thus it is historically important, even if it immediately strikes one as fishy. The argument turns on two principles, which I call substitution and redistribution. In “Semantic Innocence and Uncompromising Situations,”6 Jon Barwise and I rejected both principles, as part of our attempt..

'I never can catch myself at any time without a perception, and never can observe any thing but the perception.' These famous words of David Hume, on his inability to perceive the self, set the stage for JeeLoo Liu and John Perry's collection of essays on self-awareness and self-knowledge. This volume connects recent scientific studies on consciousness with the traditional issues about the self explored by Descartes, Locke and Hume. Experts in the field offer contrasting perspectives on matters such as the relation between consciousness and self-awareness, the notion of personhood and the epistemic access to one's own thoughts, desires or attitudes. The volume will be of interest to philosophers, psychologists, neuroscientists, cognitive scientists and others working on the central topics of consciousness and the self.

Kaplan says that monsters violate Principle 2 of his theory. Principle 2 is that indexicals, pure and demonstrative alike, are directly referential. In providing this explanation of there being no monsters, Kaplan feels his theory has an advantage over double-indexing theories like Kamp’s or Segerberg’s (or Stalnaker’s), which either embrace monsters or avoid them only by ad hoc stipulation, in the sharp conceptual distinction it draws between circumstances of evaluation and contexts of utterance. We shall argue that Kaplan’s prohibition is also essentially stipulative, and that it is too general. The main difference between ourselves and Kaplan is that the basic carriers of a truth-value is a sentence-in-a-context; our account is utterance-based.

Epistemic modal predicate logic raises conceptual problems not faced in the case of alethic modal predicate logic : Frege’s “Hesperus-Phosphorus” problem—how to make sense of ascribing to agents ignorance of necessarily true identity statements—and the related “Hintikka-Kripke” problem—how to set up a logical system combining epistemic and alethic modalities, as well as others problems, such as Quine’s “Double Vision” problem and problems of self-knowledge. In this paper, we lay out a philosophical approach to epistemic predicate logic, implemented formally in Melvin Fitting’s First-Order Intensional Logic, that we argue solves these and other conceptual problems. Topics covered include: Quine on the “collapse” of modal distinctions; the rigidity of names; belief reports and unarticulated constituents; epistemic roles; counterfactual attitudes; representational vs. interpretational semantics; ignorance of co-reference vs. ignorance of identity; two-dimensional epistemic models; quantification into epistemic contexts; and an approach to multi-agent epistemic logic based on centered worlds and hybrid logic

In §8 of hisBegriffsschrift(1879), Gottlob Frege discusses issues related to identity. Frege begins his most famous essay,“On Sense and Denotation”(1892),published 13 years later, by criticizing the view advocated in §8. He returns to theseissues in the concluding paragraph. Controversies continue over these importantpassages. We offer an interpretation and discuss some alternatives. We defend thatin theBegriffsschrift,Frege does not hold that identity is a relation between signs.§8 of theBegriffsschriftis motivated by the conflict between two differentcriteria for sameness of conceptual content of sentences. To resolve that conflict,Frege introduces‘≡’in §8 and, thus, circumstances with names as constituents. Tothe same end, in“On Sense and Denotation,”Frege introduces senses andThoughts and abandons both ‘≡’ and circumstances. He solves what we call theCo-instantiation problem, and disregards, but does not solve, the Name problem.

The latest trend in ethics, sometimes dismissed as a fad, is the effort to connect ethics to empirical science. Two different versions of this “latest thing” can be found in the work of Jonathan Haidt and Joshua Greene. Their projects are, at least partly, unwitting recoveries of eighteenth-century Christian moral sense theory. Such similarities need not worry Christian ethicists but should instead inspire a careful retrieval of sentimentalism. It provides much of what today’s empirical ethicists hope to deliver without the pitfalls.

Demonstratives seem to have posed a severe difficulty for Frege’s philosophy of language, to which his doctrine of incommunicable senses was a reaction. In “The Thought,” Frege briefly discusses sentences containing such demonstratives as “today,” “here,” and “yesterday,” and then turns to certain questions that he says are raised by the occurrence of “I” in sentences (T, 24-26). He is led to say that, when one thinks about oneself, one grasps thoughts that others cannot grasp, that cannot be communicated. However, nothing could be more out of the spirit of Frege’s account of sense and thought than an incommunicable, private thought. In the first part of the paper, I explain the problem demonstratives pose for Frege, and explore three ways he might have dealt with it. I argue that none of these ways provides Frege with a solution to his problem consistent with his philosophy of language. The first two are plausible as solutions, but contradict his identification of the sense expressed by a sentence with a thought. The third preserves the identification, but is implausible. In the second part, I suggest that Frege was led to his doctrine of incommunicable senses as a result of some appreciation of the difficulties his account of demonstratives faces, for these come quickly to the surface when we think about “I.” I argue that incommunicable senses won’t help. I end by trying to identify the central problem with Frege’s approach, and sketching an alternative.