Spring 2015, MW 12-1:20
Classroom: VKC 207
Office hours: MW 1:30 - 2:30, and by appointment
Prof. Kadri Vihvelin
MHP 212, 740-5185
vihvelin@usc.edu
Philosophy 362
Possible Worlds
We think of ourselves as living in a world of possibilities; we think that what
actually happens is not the only thing that could have happened. We think that we have
free will, and having free will means having and making choices between different
possible courses of action. But we also think about possibility in a wider sense when we
wonder how the world would now be different if the past had been different in some way
-- if Kennedy had not been assassinated, if Hitler had won the war, if the dinosaurs had
not gone extinct. And scientists think about possibility in a wider sense when they ask
whether time travel is possible given the laws of physics. And we think about possibility
in an even wider sense when we ask whether time travel is logically possible and whether
the truth of determinism is compatible with the existence of free will.
We take possibilities for granted. But it is easy to become confused when we
raise questions about possibility, necessity, and impossibility -- about what might have
been, what would have to have been, and what could never be. Philosophers use possible
worlds as a tool for asking and answering these questions, and logicians have developed
possible worlds semantics as a way of enriching our understanding of modal logic (the
logic of possibility and necessity) and the logic of counterfactual conditionals.
This course is an introduction to possible worlds and to the logic of possibility,
necessity, and counterfactuals. No prior knowledge of either logic or philosophy will be
assumed, and we won't be doing any proofs. The goal of the course is to enrich your
understanding of these concepts and to apply this understanding to a wide range of
philosophical questions, including the following: Is time travel possible? If there are
truths about our future actions does this mean that we must do whatever we end up
doing? How can we have knowledge of mere possibilities? Could you have been a
butterfly? Are there really any possible worlds and if so, what kind of things are they?
We will be reading texts by philosophers defending a diverse range of answers to these
questions. By comparing and contrasting their answers, you will improve your own
ability to think about these complex and difficult questions. You will also improve your
critical reading, thinking, and writing skills.
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Required Readings (available on Blackboard):
Adams, "Must God Create the Best?
Armstrong, "A Combinatorial Theory of Possibility"
Black, "The Identity of Indiscernibles"
Bigelow, "Time Travel Fiction"
Bradley and Swartz, Possible Worlds: An Introduction to Logic and its Philosophy: Chap.
1, excerpts from Chaps. 2 and 3
Horwich, "Lewis's Programme"
Konyndyk, Introductory Modal Logic, Chap.1, excerpt from Chap.2
Kripke, Naming and Necessity, pp. 15-21, 34-53
Lewis, "Counterfactual Dependence and Time's Arrow" (excerpt)
Lewis, "Counterparts or Double Lives?" (excerpt)
Lewis, "Possible Worlds"
Lewis, "The Paradoxes of Time Travel"
Melia, Modality, Chap.1, "Introduction to Modality"
Menzies, "Counterfactual Theories of Causation"
Shoemaker, "Time without Change"
Sider, "Reductive Theories of Modality"
Stalnaker, "Realism about Counterfactuals"
Taylor, "Fate"
Vihvelin, "What Time Travelers Cannot Do"
Vihvelin, "Killing Time Again" (excerpts)
Vihvelin, "Why the Logical Fatalist is Confused"
Vihvelin, "A Simplified Guide to the Logic of Counterfactuals"
Williams, "The Self and the Future"
SCHEDULE OF READINGS (subject to adjustments as needed):
Weeks 1-2 WAYS THINGS COULD HAVE BEEN: POSSIBLE WORLDS
AS A TOOL FOR PHILOSOPHERS
Jan. 12
Overview of course, goals, class format and methodology
Jan. 14
Bradley & Swartz, Chap. 1, pp. 1-8, "This and other Possible Worlds"
Bradley & Swartz, pp. 62-64, "The Possible Worlds Idiom"
Homework: Bradley & Swartz, pp. 8-9, Exercise A
Jan. 19
No class (University holiday)
Jan. 21
Melia, "Introduction to Modality"
Homework: Bradley & Swartz, p. 9, Exercise B
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Week 3
PROPOSITIONS AND THEIR MODAL PROPERTIES
Jan. 26 Bradley & Swartz, Chap. 1, pp. 10-27
Homework: Bradley & Swartz, pp. 24-25, Exercises 1-2
p. 27, Exercises 1, 2, 3
Jan. 28 Konyndyk, Chap. 1, "Propositional Logic", pp. 3-10
Konyndyk, Chap. 2, "Propositional Modal Logic", pp. 11-16
Homework: Bradley & Swartz, p. 27, Exercises 4, 5, 6, 7
Weeks 4-5
MODAL RELATIONS BETWEEN PROPOSITIONS
Feb. 2
Bradley and Swartz, Chap. 1, pp. 28-40
Homework: Bradley & Swartz, pp. 40-41, Exercises 1-3
Feb. 4
Bradley & Swartz, pp.41-55
Homework:Bradley & Swartz, p. 55, Part A, Exercises 1-14
Feb. 9 Konyndyk, Chap.2, pp. 16-21
Homework: Konyndyk, pp. 19-20, Exercises A, B, C.
Feb. 11 Homework: Bradley & Swartz, pp. 55-56, Part A, Exercises 15-45
Part B, Exercises 49-55
Week 6 POSSIBILITY, IMPOSSIBILITY, NECESSITY, AND
KNOWLEDGE
Feb. 16 No class (University holiday)
Feb. 18 Kripke, Naming and Necessity, pp. 34-40
Bradley & Swartz, Chap. 3, pp. 130-138
Homework: B & S, pp.138-139, Exercises 1-8
Week 7 MIDTERM and the PROBLEM OF EVIL
Feb. 23 Midterm
Feb. 25
Adams, "Must God Create the Best?"
Week 8 THOUGHT EXPERIMENTS AND POSSIBLE WORLDS
March 2 Shoemaker, "Time Without Change"
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March 4 Williams, "The Self and the Future"
Black, "The Identity of Indiscernibles"
TOPICS FOR PAPER #1 distributed
Week 9
"WILL", "MUST", and "CAN" (LOGICAL FATALISM)
March 9 Taylor, "Fate"
Bradley & Swartz, Chap.2, pp.104-107, "The Omnitemporality of Truth"
March 11 Konyndyk, Chap. 2, pp. 21-23
Vihvelin, Why the Logical Fatalist is Confused
Homework: Bradley & Swartz, p.107
March 16 & 18 No class (Spring break)
Week 10
COUNTERFACTUALS
March 23 Vihvelin, A Simplified Guide to the Logic of Counterfactuals
March 25
Stalnaker, "Realism about Counterfactuals"
PAPER #1 DUE
Week 11 CAUSATION AND COUNTERFACTUALS
March 30 Lewis, "Counterfactual Dependence and Time's Arrow" (excerpt)
Menzies, "Counterfactual Theories of Causation"
Apr. 1
Horwich, "Lewis's Programme"
Week 12 IS TIME TRAVEL POSSIBLE?
Apr. 6
Lewis, "The Paradoxes of Time Travel"
Vihvelin, "What Time Travelers Cannot Do"
TOPICS FOR PAPER #2 distributed
Apr. 8
Bigelow, "Time Travel Fiction"
Week 13 COULD YOU HAVE BEEN A BUTTERFLY?
Apr. 13 Kripke excerpt from Naming and Necessity, pp.41-53
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Apr. 15 Lewis, "Counterparts or Double Lives?" (excerpt)
Weeks 14-15 ARE THERE REALLY ANY POSSIBLE WORLDS? IF SO,
WHAT KIND OF THINGS ARE THEY?
Apr. 20 Kripke, excerpt from Naming and Necessity, pp. 15-21
Lewis, "Possible Worlds"
PAPER #2 DUE
Apr. 22
Armstrong, "A Combinatorial Theory of Possibility"
Apr. 27 Sider, "Reductive Theories of Modality
Apr. 29
Concluding Remarks
TOPICS FOR PAPER #3
COURSE REQUIREMENTS:
You are required to read the assigned readings, to attend all classes, and to do the
homework exercises for weeks 1- 5 and 9. There is a midterm. You are required to write
3 short papers (5-6 pages each). The paper topics will be distributed at least two weeks
before the paper is due.
EVALUATION AND DATES:
Midterm
Paper #1
Paper #2
Paper #3
Homework and class participation
15%
25%
25%
25%
10%
Feb. 23
(due March 25, in class
(due Apr. 20, in class
(due May 8, by email)
You must satisfactorily complete all assigned work in order to get credit for the course.
STATEMENT ON ACADEMIC CONDUCT AND SUPPORT SYSTEMS:
Plagiarism – presenting someone else’s ideas as your own, either verbatim or recast in
your own words – is a serious academic offense with serious consequences. Please
familiarize yourself with the discussion of plagiarism in SCampus in Section 11,
Behavior Violating University Standards. Other forms of academic dishonesty are
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equally unacceptable. See additional information in SCampus and university policies on
scientific misconduct.
Discrimination, sexual assault, and harassment are not tolerated by the university. You
are encouraged to report any incidents to the Office of Equity and Diversity. This is
important for the safety of the whole USC community. Another member of the university
community – such as a friend, classmate, advisor, or faculty member – can help initiate
the report, or can initiate the report on behalf of another person. The Center for Women
and Men provides 24/7 confidential support, and the sexual assault resource center
describes reporting options and other resources.
A number of USC’s schools provide support for students who need help with scholarly
writing. Check with your advisor or program staff to find out more. Students whose
primary language is not English should check with the American Language Institute,
which sponsors courses and workshops specifically for international graduate students.
The Office of Disability Services and Programs provides certification for students with
disabilities and helps arrange the relevant accommodations. If an officially declared
emergency makes travel to campus infeasible, USC Emergency Information will provide
safety and other updates, including ways in which instruction will be continued by means
of blackboard, teleconferencing, and other technology.
POLICIES:
The paper topics will be distributed at least two weeks before the paper is due.
Rewrites will not be permitted except in unusual circumstances, but I will provide written
comments on drafts, if requested. I will accept late papers, but unless you have a very
good excuse your grade will be dropped one notch (eg. from an A to an A-) for each day
that the paper is late. It is your responsibility to save all returned papers until you get
your official grade for the course.
If you require academic accomodations based on a disability please inform me (as
well as Disability Services and Programs) as early in the semester as possible, so that I
can make whatever arrangements are necessary.
Universities policies concerning “incompletes” will be strictly observed. You may
not receive a grade of “IN” unless you are very ill or face a genuine emergency.
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