Philosophy | Seminar in Logical Theory
P751 | 3258 | Barwise

Topic: Logical Consequence

Note: This course carries 4 credit hours.

The central topic of the seminar will be that of logical consequence.  What does it mean
for one sentence to be a logical consequence of another?  The standard answer to this is
usually taken to be given to Tarski's famous analysis of the notion.  We will start by
reading Tarski's analysis.

A few years ago, John Etchemendy published the book The Concept of Logical
Consequence, where he argued that Tarski's famous analysis is wrong on conceptual
grounds.  This book had recently been reprinted and so is now available again.  The
central portion of the course will be devoted to going through Etchemendy's argument.

Since the publication of Etchemendy's book, many authors have published attacks on
Etchemendy's argument, attempts to salvage Tarski's analysis by finding an error in the
argument.  Interestingly, they seem to find the error in very different places.  We will
read a selection of these rebuttals.

Etchemendy has recently written a follow-up article, based on his failure to be convinced
by any of the rebuttals.  In this paper he both summarizes his argument against the
Tarskian account, in light of what he takes to be misunderstandings of it, ang goes on to
sketch his positive view of how to develop a theory of logical consequence.  We will also
read this paper.

If time permits, we will also read some other related papers.

Students will be expected to lead seminar discussions and to write a term paper on a topic
closely related to that of the seminar.

Prerequisites:  Elementary set theory and first-order logic (up through the completeness
theorem).  Students who have successfully completed P505 meet the prerequisite.