Philosophy 520: Philosophical Applications of Symbolic Logic

 

Dr. McGrew, Spring 2007

 

Required Texts: There are two required texts for this course: E. J. Lemmon, Beginning Logic, and Susan Haack, Philosophy of Logics. Additional material (which is fair game for tests and quizzes) will be passed out in class or made available on the web. Students are responsible to get internet access through WMU (it's free) and make use of it to obtain relevant materials as assigned. The web address for this class is: 

 

       http://homepages.wmich.edu/~mcgrew/GradLogic07.htm

 

Course Description: In the twentieth century, symbolic logic has become the philosopher’s analytical tool par excellence. The aim of this course is to give students a firm understanding of elementary symbolic logic through the first order predicate calculus and to explore extensions of elementary logic such as second-order logic with identity, the family of modal logics, deontic logic, epistemic logic, and tense logic, as well as variants like many-valued logics and probability logic and even more exotic systems like protothetic. Along the way we will give considerable attention to philosophical issues involving the interpretation of logical notions, the interplay between logic and the history of philosophy, and some central questions in the epistemology of logic. By the end of the course, students should have a clear sense of the scope of elementary logic, facility in its use, an understanding of the relations between elementary logic and some of its more prominent extensions and variants, and an understanding of the implications of the basic metatheoretical results.

 

This is a graduate course that presupposes a prior course in symbolic logic at the level of Phil 225 or (preferably) Phil 320. We will move rapidly and the material covered will, at times, be more difficult than that in the average graduate seminar. Exams will include proofs and  translations as well as conceptual questions. Students who are unable or unwilling to do this sort of work are strongly urged to take some other course.

 

Course Requirements: This course meets Tuesday and Thursday of each week at 2:00 p.m. except for scheduled holidays. Missed exams and quizzes cannot generally be made up without a medical excuse. Attendance and class participation are taken into account in the determination of the final grade. In particular, I reserve the right to subtract five points from the final semester grade for each unexcused absence beyond the third. Students are expected to come to class having done the reading indicated on the syllabus and may be subjected to quizzes without notice.

 

Academic Integrity: You are responsible for making yourself aware of and understanding the university’s policies and procedures that pertain to Academic Integrity. These policies include cheating, fabrication, falsification and forgery, multiple submission, plagiarism, complicity and computer misuse. If there is reason to believe you have been involved in academic dishonesty, you will be referred to the Office of Student Conduct. You will be given the opportunity to review the charge(s). If you believe you are not responsible, you will have the opportunity for a hearing. You should consult with me if you are uncertain about an issue of academic honesty prior to the submission of an assignment or test.

 

Grading:  Aside from attendance, the course grade will be based on two exams in the middle of the semester, homework and pop quizzes (if any), and a final. The exams will be weighted equally at 25% of the grade apiece. The grading scale is:

 

 

A            93-100

B            83-87

C            73-77

D     60-67

B/A        88-92

C/B        78-82

D/C        68-72

E     below 60

 

 

COURSE SCHEDULE

 

Note: The following course schedule is tentative. Because the material is difficult, some of it may take longer than the indicated time. You are expected to do the readings in accordance with the sequence of topics even if we are off schedule. Any alterations in examination dates will be announced in class ahead of time.

 

(1-3) Propositional Logic

 

Week 1: Jan 9, 11

 

Indroduction to the course. A map of some logical systems and their relation to classical bivalent propositional logic. The syntax of propositional logic. Formation rules. Basic inference rules.

 

Reading: Lemmon, ch 1; class handout

 

Week 2: Jan 16, 18

 

Semantics of propositional logic. Derived sequents, shortcuts, and proof strategy in natural deduction. Counterexampling through semantic models. Semantic tableaux.

 

Reading: Lemmon, ch 2, pp. 42-64; class handouts; Proof Strategy

 

Week 3: Jan 23, 25

 

Truth-functionality, functional completeness and disjunctive normal form. Formal semantics for propositional logic. Truth under an interpretation. Polish notation for propositional logic.

 

Reading: Lemmon, ch 2, pp. 64-74, Logic Made Difficult

 

(4) Semantic Issues in Propositional Logic

 

Week 4: Jan 30, Feb 1

 

The connection between formal connectives and natural language counterparts. Non-truth-functionality of subjunctive conditionals. The indicative conditional and the paradoxes of material implication. Assertability, implicature, and robustness.

 

Readings: Haack, ch 3; Class Handouts

 

(5) Metatheory of Propositional Logic

 

Week 5: Feb 6, 8

 

Metatheoretic properties: soundness (consistency) and completeness. The relation between syntax and semantics.

 

Reading: Lemmon, ch 2, pp. 75-91; Class Handouts

 

First Exam

 

Here is the first Extra Credit Assignment!

 

(6-8) Modal and Quasi-modal Extensions of Propositional Logic

 

Week 6: Feb 13, 15

 

Modal extensions of propositional logic. Formation rules and semantics of the ~ and  operators. Possible worlds. Difficulties in the interpretation of modal sentence logic.

 

Reading: Haack, ch 10, pp. 170-82

 

Week 7: Feb 20, 22

 

Hierarchy of modal inference systems. Modal systems as models of semantic notions (e.g. analyticity). Reiteration and Tarski. Modal semantics for counterfactuals.

 

Reading: Class Handouts

 

Week 8: Feb 27, Mar 1

 

Quasi-modal operators. Deontic logic, epistemic logic, and tense logic. Aristotelian conception of the bearers of truth; related conception of necessity.

 

Reading: Class Handouts

 

Mar 5-11: Spring Break

 

(9) Many-valued Logics

 

Week 9: Mar 13, 15

 

Alternative valuations systems for propositional logic. Fatalism, indeterminism, and Lukasiewicz’s three-valued logic. Probability logic.

 

Reading: Haack, ch 11; Class Handouts

 

Second Exam

 

(10-11) Predicate Calculus

 

Week 10: Mar 20, 22

 

Predicate logic. Syntax and formation rules of predicate logic. Basic inference rules, derived sequents, and proof strategy.

 

Reading: Lemmon, ch 3

 

Week 11: Mar 27, 29

 

Second order quantification. Basic metatheoretical results.

 

Reading: Class Handouts

 

(12) Semantics of the Predicate Calculus

 

Week 12: Apr 3, 5

 

Truth under an interpretation. Substitutional vs. objectual semantics. Polish notation for predicate logic.

 

Reading: Haack, ch 4; Class Handouts

 

(13) Modal Extension of the Predicate Calculus

 

Week 13: Apr 10, 12

 

Quantified modal logic and essentialism. Quine’s three grades of modal involvement. The analysis of definite descriptions. Possible worlds once again.

 

Reading: Haack, ch 10, pp. 182-94

 

(14) Protothetic Extension of the Predicate Calculus

 

Week 14: Apr 17, 19

 

Protothetic and the representation of self-reference and self-refutation.

 

Reading: Class Handouts

 

Final Exam Due Wed, April 25