That was funny

Here is a list of the ways professors grade their final exams:

DEPT OF STATISTICS:
All grades are plotted along the normal bell curve.

DEPT OF PSYCHOLOGY:
Students are asked to blot ink in their exam books, close them and turn them in. The professor opens the books and assigns the first grade that comes to mind.

DEPT OF HISTORY:
All students get the same grade they got last year.

DEPT OF PHILOSOPHY:
What is a grade?

DEPT OF MATHEMATICS:
Grades are variable.

DEPT OF LOGIC:
If and only if the student is present for the final and the student has accumulated a passing grade then the student will receive an A else the student will not receive an A.

DEPT OF COMPUTER SCIENCE:
Random number generator determines grade.

MUSIC DEPARTMENT:
Each student must figure out his grade by listening to the instructor play the corresponding note (+ and – would be sharp and flat respectively).

LAW SCHOOL:
Students are asked to defend their position of why they should receive an A.