In a well-known, controversial paper, Professor Robert J. Aumann (1995) gave a formal presentation and a proof of the claim, that in games with perfect information, common knowledge of rationality implies that the backward induction outcome is reached. What keeps the players in Aumann’s model from deviating from the backward induction path is the following. Each player knows that if he deviates...

The Argument Interchange Format (AIF) has been devised in order to support the interchange of ideas and data between different projects and applications in the area of computational argumentation. In order to support such interchange, an abstract ontology for argumentation is presented, which serves as an interlingua between various more concrete argumentation languages. In this paper, we aim t...

Recent developments in cosmology indicate that every history having a nonzero probability is realized in infinitely many distinct regions of spacetime. Thus, it appears that the universe contains infinitely many civilizations exactly like our own, as well as infinitely many civilizations that differ from our own in any way permitted by physical laws. We explore the implications of this conclusi...

I’ll raise a problem for Retributivism, the view that legal punishment is justified on the basis of desert. I’ll focus primarily on Mitchell Berman’s recent defense of the view. He gives one of the most sophisticated and careful statements of it. And his argument is representative, so the problem I’ll raise for it will apply to other versions of Retributivism. His insights about justification a...

We explore a framework for argumentation (based on classical logic) in which an argument is a pair where the first item in the pair is a minimal consistent set of formulae that proves the second item (which is a formula). We provide some basic definitions for arguments, and various kinds of counter-arguments (defeaters). This leads us to the definition of canonical undercuts which we argue are ...

The existence of null arguments in Athabascan languages, and other polysynthetic languages, is a debated topic. We argue that, if the agreement on the verb is the argument, the so-called Pronominal Argument Hypothesis, languages such as Navajo do not have null arguments in the traditional sense. We then outline the diachrony of Athabascan object marking on the verb (by looking at the various co...

After determining one set of skills that we hoped our students were learning in the introductory philosophy class at Carnegie Mellon University, we designed an experiment to test whether they were actually learning these skills. In addition, there were four sections of this course in the Spring of 2004, and the students in Section 1 were taught the material using argument diagrams as a tool to ...

The slippery slope argument (SSA) is generally treated as a fallacy by both traditional and contemporary theories of argumentation, but is frequently used and widely accepted in applied reasoning domains. Experiment 1 tests the hypothesis that SSAs are not perceived as universally weak arguments. The results provide the first empirical demonstration that SSAs vary predictably in their subjectiv...