Level of study Second Year
Credit value 20
Pre-requisite modules 40 credits of philosophy
Other pre-requisites A basic knowledge of first-order logic is required. (Most UK universities and many overseas require first-year philosophy students to take a basic log
After a general introduction in which the basics are explained and related to topics from last year’s Logic modules, we begin with some issues thrown up by philosophical reflection on classical logic itself. To get started on this we evaluate different accounts of the meanings of the familiar logical connectives (e.g. ‘&’, ‘v’, and especially, ‘→’). Next we move to consider the most instructive extension of classical logic: modal logic. This is logic designed to codify reasoning involving 'modal' notions - most paradigmatically those of necessity and possibility, but it may also be utilized to cover reasoning involving e.g. knowledge, time and moral obligation. After that we look at one of the most notorious logical paradoxes, the Liar Paradox, and consider some further non-classical logics - those that accommodate propositions which are neither true nor false, or which are both true and false.
The main topic for the second half of the module is semantics, the study of the relation between thoughts/words and the worldly items they represent. After preparing the ground by reprising the apparatus of quantification (and taking a brief look in passing at some puzzles about identity) we consider the classic debate between theorists who consider the relation between a singular term and its referent to be direct, and those who hold it to be mediated by something like the speaker’s conception of the referent. Next we consider Russell’s famous theory of descriptions, and the debate between philosophers who extend and apply that theory so as to yield a theory of the semantics of singular terms generally, and their critics (in particular, Kripke). We end with a topic which involves logic and semantics in equal measure: how to account for the apparently paradoxical character of sentences which purport to deny the existence of things. (e.g. ‘Pegasus does not exist’).