PHIL 2140 - Introduction to Logic

Course Overview

First things first: Is this the right course for me?

Students are sometimes telling me at the end of the course that they had expected something quite different from this course than what they ended up getting. To avoid this, let me say a few things about the scope of this course, and how it differs from some other related courses, in particular the course PHIL/PSYC-2100 Methods of Reasoning.

Traditionally, logic is the study of reasoning. In particular, logic tries to tell us what is good reasoning, and what is bad reasoning. Thus, logic is a normative theory of how one should reason, rather than a descriptive theory of how we humans actually reason. PHIL/PSYC-2100 Methods of Reasoning is a course on how humans actually reason (hence it is cross-listed under Psychology as well as Philosophy), while this course (Introduction to Logic) is a course on how one should reason.

This course, Introduction to Logic, is really an introduction to formal logic, which lays out formal systems that can be used to analyze reasoning. There are a few important consequences to such a purely formal approach that you should know about:

First of all, this course has a distinct flavor of both (discrete) mathematics and computer science: there are abstract symbols to form complex expressions, precisely defined operations to manipulate those expressions, and systematic procedures to perform sequences of these operations. If you like that kind of material, and/or you like doing abstract logic puzzles, you'll love this course. On the other hand, if your aim is to analyze everyday life reasoning, where answers are far less clear cut, and you are dealing with gray areas and fuzzy boundaries, you may want to take PHIL/PSYC-2100 Methods of Reasoning.

Second, the application of formal systems of logic doesn't lie so much in the analysis of reasoning, as it lies in its ability to precisely represent and manipulate information. Thus, formal logic is used in mathematics as a way to avoid the ambiguities of the English language in expressing certain mathematical claims, as well as to organize and formalize mathematical proofs. Formal logic is also what underlies the whole field of computer science, and formal logic can be explicitly found at both computer hardware (think logic gates) and software (think Artificial Intelligence). Indeed, follow-up courses to this course, such as PHIL-4140 Intermediate Logic, PHIL-4420 Computability and Logic, and PHIL-6240 Logic and AI, all continue on these themes. And, finally, LSAT and GRE tests like to ask questions that have clear-cut answers, so you'll find the kinds of logic problems we do in this course reflected in those tests. So again, if you like mathematics, computer science, or want 'hard' answers, take this course. On the other hand, if you are more drawn to philosophy or psychology, take PHIL/PSYC-2100 Methods of Reasoning.