Philosophers know their arguments and assumptions (and those of others as well). They can communicate effectively to large groups, and know how to appeal to others (to recruit new members, get a book deal or a paid interview) . They are familiar with memetic techniques and know how to recognize them. They are also familiar with picking apart and formulating logical arguments.
The memetic aspects of this Profession, argument and deeper aspects of a philosophy, are considered specialized tasks.
Why, yes I did crib from Religious. Why do you ask? ;-)