PHIL 139b: Topics in Logic: Conditionals

When: Tues. and Fri. 11:00-12:20

Where: Olin-Sang 112

Who: Professor Jennifer Marusic

Office Hours: Tuesdays 2pm-4pm

Office: 112 Mandel Center for the Humanities

Course Description

This class will explore in greater depth the philosophical significance of some of the concepts you learned in logic. While the class will include some technical material, we’ll spend the bulk of the semester thinking about philosophical problems and questions that arise in symbolic logic. Accordingly, the course requirements will include problem sets and a research paper. The class will be divided into four parts: on indicative conditionals,on counterfactual conditionals, on counterpossible conditionals, and on the relationship between indicative and counterfactuals.

Part 1: Indicative Conditionals

In logic, we learn that a conditional is false if and only if it has a true antecedent and a false consequent. Conditionals with these truth conditions are known as material conditionals. While treating ordinary language conditionals as the material conditional has enormous logical power, it is controversial whether ordinary, indicative conditionals really are material conditionals.

For example, is the conditional,

(1)If the moon is made of cheese, then 2+2=5,

really true? Or is an indicative conditional true only if there is some sort of relationship or connection between the antecedent and consequent? If so, what kind of connection is required? If indicative conditionals really are material conditionals, how can we explain why (1) sounds so strange?

Part 2: Counterfactual Conditionals

There is an important class of conditionals—known as counterfactual or subjunctive conditionals—that clearly cannot be analyzed as the material conditional.

Examples of counterfactuals are:

(2)If this match weren’t wet, it would’ve lit when it was struck.

(3)If we had not passed a stimulus bill, the economy would be much worse now than it is.

Counterfactuals cannot be treated as material conditionals because they are acknowledged to have false antecedents—the match is wet and we did pass a stimulus bill—and yet we don’t take all of them to be true. We’ll consider different approaches to counterfactuals and consider a number of philosophical issues connected to these approaches, such as the nature of possible worlds and our knowledge about them.

Part 3: Counterpossible Conditionals

As we’ll see, the standard semantics for counterfactual conditionals count as true all counterfactuals with necessarily false antecedents. But it seems that there are cases where we don’t treat all such conditionals as trivially true. We’ll look at a few recent attempts to explore these sorts of conditionals and their significance.

Part 4: Are There Really Two Types of Conditionals?

In the last part of the class, we’ll return to our initial starting point and consider whether there really are two distinct kinds of conditionals, indicatives and counterfactuals, and, if so, how the two kinds are related, if at all. We’ll look at recent attempts to offer a unified account of conditionals.

Requirements

There will be a take-home exam at the end of the first two parts of the course. Each exam will include both short-answer essay questions and more technical logic exercises. In addition, there will be a 5-7 page research paper due at the end of the semester on a topic of your choosing. You will be asked to turn in a proposal for this research paper at least two weeks before the paper is due.

Grading

The take-home exams will be worth 60% of the grade for the class. The research paper will be worth 30% of the grade and participation will be worth the remaining 10%.

Late exams and papers will be deducted one third of a grade (e.g. from a B to a B-) for each day they are late. No assignments will be accepted more than one week late. If you need an extension on an assignment, perhaps because you have work due in other classes on the same day or for personal reasons, please ask me. I am willing to grant short extensions, provided you ask for them at least a full day in advance. If you are unable to complete an assignment on time because of an unexpected illness, please let me know as soon as possible.

You should come to class prepared, having done the readings in advance. You should bring the texts with you to class! We will frequently be referring to the texts during class, so it is important that you have them.

Readings

There is one required text for the course. Additional readings will be posted on LATTE or distributed in class.

The required book is:

Jonathan Bennett. A Philosophical Guide to Conditionals. Oxford: 2003.

Disability. If you are a student with a documented disability at Brandeis University and wish to have a reasonable accommodation made for you in this class, please see the course instructor immediately.

Academic Honesty. You are expected to be honest in all of your academic work. The University policy on academic honesty is distributed annually as section 5 of the Rights and Responsibilities handbook. Instances of alleged dishonesty will be forwarded to the Office of Campus Life for possible referral to the Student Judicial System. Potential sanctions include failure in the course and suspension from the University. If you have any questions about my expectations, please ask.

Four-Credit Course (with three hours of class-time per week). Success in this 4 credit hour course is based on the expectation that students will spend a minimum of 9 hours of study time per week in preparation for class (readings, doing exercises, problem sets, discussion sections, preparation for exams, etc.).

Communications. The course will have a mailing list on LATTE. Information about snow days, changed deadlines, and so forth will be broadcast on that mailing list. We may make use of LATTE discussion forums as well.

Schedule

The following is a rough guide to the topics we’ll cover in the class and the approximate amount of time I’d like to spend on each one. I will distribute a more detailed schedule with specific readings at the start of each unit. The schedule and readings may change substantially as we go, depending on student interests.

Introduction: Two Kinds of Conditionals? August 30th

Reading: A Philosophical Guide to Conditionals, Chapter 1, and Dorothy Edginton, “On Conditionals,” Mind (1995), pp. 235-244 (stop at end of section 2.4).

Unit 1: Indicative Conditionals: Sept. 2nd-Oct. 11th

Reading: Conditionals, Chapters 2-9, and various primary reading.

Unit 2: Counterfactual Conditionals: Oct. 14-Nov. 11th

Reading: Conditionals, Chapters 10-16, 18-20, and various primary reading.

Unit 3: Counterpossible Conditionals: Nov. 15h-Nov. 22nd

Reading: Recent papers by Matthias Jenny, Kenny Pearce, and Brogaard and Salerno.

Unit 4: Are There Really Two Types of Conditionals? Nov. 29th-Dec. 6th

Reading: Conditionals, Chapters 22-23, and various primary reading.