<p>We all hear of some of the "infamously impossible courses" of each subject area. For example, in chemistry/pre-med it's organic chem, in physics it's Quantum Mechanics, in math it's Real Analysis (or some redonculously high level of Calc). I was wondering if anybody could enlighten me of the hardest classes at this school. For example, what is the hardest class/greatest challenge in a field such as Poly Sci, IR, Woodrow Wilson (for Princeton's case), Sociology, Econ, Psych, English? What Philosopher's works are considered the most difficult to read and comprehend? Etc.</p>