Saunders Mac Lane

Category Theory

80-413/713 — Fall 2023

Time: TR 14:00–15:20
Room: GHC 4215


Teaching Assistants:

Samuel Eilenberg

Office Hours



Course Description

Category theory is a formal discipline developed to study complex problems in algebra and geometry, and later applied in logic, physics, computer science and many other areas. As such, this course will be more like a math class than a typical philosophy section. In particular, students will be expected to provide formal arguments and proofs for homework and on tests.


Steve Awodey, Category Theory, 2nd edition, Oxford University Press, 2010.

We will follow the book quite closely, taking about one week for each chapter.

Additional Texts & Resources


The final course grade will be calculated as follows:


Homework sets will typically consist of 3-5 problems, and will be posted here each week. In your solutions, you may appeal to any fact which has been proved either in class or in the course textbook. There will be 10-12 homework sheets in total.

Homework has to be submitted via gradescope (use the code posted on piazza), by the time indicated on the homework sheet.


The final exam will take place in classroom in the exam week at the end of the semester.

80-413 vs. 80-713

The undergraduate and graduate sections of this course will be taught together. However, students enrolled in the graduate section will be expected to work a little bit harder. Each homework set will contain 1-2 starred problems that only the 80-713 students will be expected to solve. The tests may also have additional starred problems.