Philosophy should be under humanities... for instance, here is USC's take on it their Humanities pre-reqs.
"Humanities:
Baccalaureate recipients automatically fulfill this category. Students who will not be earning a Baccalaureate degree must complete additional 2 semesters/3 quarters of courses. Courses in history, literature, philosophy, religion, fine arts appreciation/history), classics and ethics may be used to fulfill this requirement."