Steve Kuhn

A simple puzzle leads Fine to conclude that we should distinguish between _worldly_ sentences like “Socrates exists,” whose truth values depend on circumstances and _unworldly_ ones like “Socrates is human,” which are true or false independently of circumstances. The former, if true in every circumstance, express necessary propositions. The latter, if true, express _transcendental_ propositions, which, for theoretical convenience, we regard as necessary in an extended sense. Here it is argued that this understanding is backwards. Transcendental truths and sentences true in every circumstance (here labeled _universal_ truths) are both species of necessary truth. The revised understanding is clarified by a simple formal system with distinct operators for necessary, transcendental, and universal truth. The system is axiomatized. Its universal-truth fragment coincides with something that Arthur Prior once proposed as _System_ __A__. The ideas of necessary, transcendental truth are further clarified by considering their interaction with actual truth. Adding an operator for _actually true_ to the formal system produces a system closely related to one of Crossley and Humberstone.

The remarkably durable construct of “modern human behavior” (MHB) is used by paleoanthropologists to summarize the features of behavior and underlying cognitive capacities that distinguish Late Pleistocene Homo sapiens from all other hominins. Some or all of these “modern” behaviors are assumed to have underpinned the ultimate demographic success of Homo sapiens. We argue that the common search for signs of modernity in the Paleolithic has inadvertently narrowed the field’s scope of inquiry. Treating MHB as the sole measure of humanness blinds us to potentially unique evolutionary trajectories followed by other hominins. In so doing, many uses of the MHB concept even compromise our attempts to understand the evolution of Homo sapiens. We offer some programmatic suggestions for investigating “non-analog” forms of behavior among hominins. We focus on the example of Middle Paleolithic Neanderthals, the hominin that paleoanthropologists know the most about other than ourselves, with an eye to the historical influences of regional biodiversity and small population sizes.

Le dilemme du prisonnier occupe une place centrale dans la théorie morale de Gauthier, mais cette place est en évolution. Dans «Morality and Advantage», ce dilemme fournit un modèle montrant comment la moralité peut avoir des propriétés apparemment contradictoires. Dans Morals by Agreement, il pose un problème particulier pour l’opinion selon laquelle un comportement moral est individuellement rationnel. Suite à ces publications, certains experts en théorie des jeux ont contesté l’idée voulant que le dilemme du prisonnier soit un cadre approprié pour réfléchir sur la théorie morale. La première partie de cet article examine les rôles du dilemme du prisonnier dans l’œuvre de Gauthier. La deuxième partie présente un projet, incluant des composantes descriptives et normatives, qui développe les idées de «Morality and Advantage» tout en le préservant de la critique des théoriciens des jeux.

The prisoner 's dilemma game has acquired large literatures in several disciplines. It is surprising, therefore, that a good definition of the game is hard to find. Typically an author relates a story about captured criminals or military rivals, provides a particular payoff matrix and asserts that the PD is characterized, or illustrated, by that matrix. In the few cases in which characterizing conditions are given, the conditions, and the motivations for them, do not always agree with each other or with the paradigm examples elsewhere. In this paper we describe several varieties of PD's. In particular, we suggest there are two distinctions among PD's with philosophical significance, the pure/impure and the utilitarian/nonutilitarian distinctions. In the first section, we explain and characterize the two distinctions. In the second, we discuss an issue of moral philosophy that illustrates the significance of the former.

A notable early result of David Makinson establishes that every monotone modal logic can be extended to LI, LV, or LF, and every antitone logic can be extended to LN, LV, or LF, where LI, LN, LV, and LF are logics axiomatized, respectively, by the schemas □α↔α, □α↔¬α, □α↔⊤, and □α↔⊥. We investigate logics that are both monotone and antitone (hereafter amphitone). There are exactly three: LV, LF, and the minimum amphitone logic AM axiomatized by the schema □α→□β. These logics, along with LI, LN, and a wider class of “extensional” logics, bear close affinities to classical propositional logic. Characterizing those affinities reveals differences among several accounts of equivalence between logics. Some results about amphitone logics do not carry over when logics are construed as consequence or generalized (“multiple-conclusion”) consequence relations on languages that may lack some or all of the nonmodal connectives. We close by discussing these divergences and conditions under which our results do carry over.

The semantics of tense has received a great deal of attention in the contemporary linguistics, philosophy and logic literatures. This is probably due partly to a renewed appreciation for the fact that issues involving tense touch on certain issues of philosophical importance (viz., determinism, causality, and the nature of events, of time and of change). It may also be due partly to neglect. Tense was noticeably omitted from the theories of meaning advanced in previous generations. In the writings of both Russell and Frege there is the suggestion that tense would be absent altogether from an ideal or scientifically adequate language. (Tense was not the only blemish of natural language to be removed, of course, but tense is a more serious omission than, say, pronouns because it is present in every sentence of the language.) Finally, in recent years there has been a greater recognition of the important role that all of the so-called “indexical” expressions must play in an explanation of mental states and human behavior. Tense is no exception. Knowing that our friend died is cause for mourning, knowing that he dies is just another confirmation of a familiar syllogism.