At the top of this hierarchy are the most general or abstract subjects: philosophy and theology; they cut across time, place, and circumstances, and they apply to a wide range of situations and experiences. Mathematics is important because it cultivates the power to deal with abstract thinking. History and literature also rank high because they are sources of moral and cultural models. Lower in the curricular ladder are the natural and physical sciences, which deal with particular cause-and-effect relationships. Language is also an important subject, because it is necessary for communication and facilitates conception of thought.