Modal logic, an extension of classical logic, investigates the modes of truth such as necessity and possibility. Its development has been closely intertwined with advances in proof theory, a field ...

As this is the fourth edition—though enlarged and partly re-written—of the work under notice, it is not necessary to review it in detail. It is sufficient to mention, by way of reminder, that for the ...

Inductive proofs; the concept of ‘a posteriori’. Cosmological argument: St Thomas Aquinas’ first Three Ways – (motion or change; cause and effect; contingency and necessity). The Kalam cosmological ...

What seem to be Kurt Gödel's first notes on logic, an exercise notebook of 84 pages, contains formal proofs in higher-order arithmetic and set theory. The choice of these topics is clearly suggested ...

The paper is concerned with the psychological relevance of a logical model for deductive reasoning. We propose a new way to analyze logical reasoning in a deductive version of the Mastermind game ...