Graeme (R.) Forbes

Filling the need for an accessible, carefully structured introductory text in symbolic logic, Modern Logic has many features designed to improve students' comprehension of the subject, including a proof system that is the same as the award-winning computer program MacLogic, and a special appendix that shows how to use MacLogic as a teaching aid. There are graded exercises at the end of each chapter--more than 900 in all--with selected answers at the end of the book. Unlike competing texts, Modern Logic gives equal weight to semantics and proof theory and explains their relationship, and develops in detail techniques for symbolizing natural language in first-order logic. After a general introduction featuring the notion of logical form, the book offers sections on classical sentential logic, monadic predicate logic, and full first-order logic with identity. A concluding section deals with extensions of and alternatives to classical logic, including modal logic, intuitionistic logic, and fuzzy logic. For students of philosophy, mathematics, computer science, or linguistics, Modern Logic provides a thorough understanding of basic concepts and a sound basis for more advanced work.

This paper is about a substitution-failure in attitude ascriptions, but not the one you think. A standard view about the semantic shape of ‘that’-clause attitude ascriptions is that they are fundamentally relational. The attitude verb expresses a binary relation whose extension, if not empty, is a collection of pairs each of which consists in an individual and a proposition, while the ‘that’-clause is a term for a proposition. One interesting problem this view faces is that, within the scope of many attitude verbs, ‘that’-clauses are not interchange able with certain other terms which stand for the same propositions as the clauses are supposed to. For example, (1a) below may be true, but (1c) is probably not: (1) a. Holmes {fears/suspects} that Moriarty has returned. b. That Moriarty has returned is the proposition that Moriarty has re turned. c. Holmes {fears/suspects} the proposition that Moriarty has returned. For only the exceptionally timorous fear propositions, and, excluding contexts in which we speak of a ‘suspect premise’, only the unusually paranoid suspect them. The truth-conditional change eVected by substituting propositional descrip tion for ‘that’- clause illustrated in (1) occurs with a wide range of attitude verbs. If you understand that the window of opportunity is closing, perhaps you should act before it is too late, but if you mere-.

In Section 1 we describe the Sorites paradox and lay out options for a solution. In Section 2 we consider approaches which deny that all premises are true, and note that these solutions all seem open to a certain serious objection. In Section 3 we note a problem for the principle of transitivity of the conditional and present a contex- tualist resolution of the problem, according to which the “counterexamples” to transitivity involve the informal fallacy of shifting the context. In Section 4 we consider the possibility of applying the contextualist resolution of the general transitivity puzzle to Sorites arguments in particular, discussing the views of Kamp, Pinkal and Soames. Our negative conclusion, developed in Section 5, is that the paradoxes can be formulated in a way that does not commit the informal fallacy: context is held fixed. In the final section, we suggest a different defense against the objection used in Section 2.

This paper in revised form appears in Facta Philosophica 5:1 (2003) 49­75. It addresses some problems about intensional transitives raised by Moltmann and Zimmerman, corrects some oversights in my paper in The Proceedings of the Aristotelian Society (S.V. for 2002), and adds new material on binary vs. tripartite construals of “relational/notional”, bridge inferences, weakening inferences, and the relevance problem. Its other sections are, like the PASS paper, concerned with the conjunctive force of disjunctive NP complements of intensional transitive verbs: “Smith needs a good lawyer or a friendly judge” on its normal reading implies both “a good lawyer could help him” AND “a friendly judge could help him”. The reading on which “Smith needs a good lawyer or a friendly judge” is implied just by “Smith needs a good lawyer” (and so doesn’t imply a friendly judge could help him) is much less preferred, except when the disjunction is followed by a coda such as “and he doesn’t care which”.