Philosophy 207: Probability and Decision  (Vailati)  Fall 2012  

Where to reach me: PH 2212; phone x3376; homepage:

Click on “courses” and then on “Probability and Decision” to find this very syllabus.

Office hours: M 11-12; T 5-6 and by appointment if needed.


Course objectives.  This course introduces student to the basic concepts of probability, decision theory, game theory, and to some of their philosophical implications.  We shall start by studying the basics of probability calculus, including Bayes’ Theorem, and investigate some of the human shortcomings in dealing with probability.  We shall then apply what we have learned to decision theory and address cases taken from real life, especially from medicine and business.  The last third of the course will be devoted to classical, behavioral, and evolutionary game theory, which we shall use to address some philosophical questions such as the nature of human beings and the origins of prosociality and morality.

The amount of mathematics required is minimal; all that students need to know is the use of fractions and the ability to solve first degree equations.



1.      B. Skirms, Choice and Chance 4th edition (Wadsworth).  Abbreviated as “S”.  This is a rental text

2.      Material to be down loaded from my homepage.

Course outline

8/20-9/5: Intro to the course; Download Probability; download Probability Exercises; a bit of theory: download Probability Spaces.   Peruse S 109-127.  Download more probability exercises.  Here are more exercises

September 3: holiday

9/5: First Quiz.


9/10-9/20: Conditional Probability and some common pitfalls in using it.  For fun, play Let’s Make a Deal.  Download Tests. Download Causation Vs. Diagnosis.  Watch Ariely’s lecture on irrationality in decision-making.


9/24-26: New evidence and the testing of theories.  Download Inductive Arguments and The Testing of Theories.  Peruse S 151-156.  Optional: Continuous Uniform Distribution.

9/26: Second Quiz.


10/1-3: Two new concepts: Normalization and Probability Density. The use of Probability in Quantum Mechanics.  Download Bets.  Peruse S 128-135.  Optional: two applications of probability to genetics: 1 and 2.


10/10: Midterm.


10/8-10/24: Decision, Risk, and some conceptual problems.  Download Decision Exercises.  Some more exercises.  The notion of Utility. A puzzle: Newcomb’s Problem.

10/24: Third Quiz.


10/29-31: Classical Game Theory.  Some Game Theory exercises.  Mini lecture on sequential games; the pitfalls of regression in sequential games: Centepide. 

10/31: Fourth Quiz.


11/5-11/14: Evolutionary Game Theory; some exercises.  An application: Rock-Paper-Scissors.  Game theory and the world: Biology and Rock-Paper-Scissors.  How do we actually play: Behavioral Game Theory.  Watch Nowak’s lecture at Harvard.


11/22 Thanksgiving


11/26-28: Evolutionary game theory in action: a game theoretical model for the rise of human cooperation and morality.


12/3-5: What is probability?

12/5: Fifth Quiz

Course Requirements:

·         Regular attendance

·         Five quizzes, some take home, some in class, each worth 8% of the course grade.  Their dates are given above.  No makeup quizzes allowed unless in extreme circumstances.

·         Four pop home-works, handed out in class, each worth 5% of the course grade.  Only those in class can do them.  No makeup unless in extreme circumstances.

·         One midterm, worth 20% of the course grade.  For date, see above.

·         A final exam, worth 20% of the course grade. 

There are 200 possible points in this class.  The correspondence with letter grades is as follows: 200-175: A; 174-145: B; 144-120: C; 119-100: D; below 100: F.

Academic Policies

Cheating of any kind will be dealt with according to the draconian CAS guidelines.

Students are responsible for knowing what has been said in class, including announcements.

No phoning, texting, surfing the web, or reading of irrelevant material.


Some Advice

If you want to do well in this class, you must put some real work into it.  This means studying (not merely glancing at) the material, and doing the exercises.  If you have difficulties, come and see me as soon as possible.  Students also profit from discussing the material with each other.