فصل في الرؤوس الثمانية
A section on the eight introductory headings.
Classical study manuals often open with eight guideposts that orient the learner before detailed treatment. They are called ruʾūs thamāniya—the eight headings.
They differ in function from subject, principles, and problems. The latter describe the science's internal structure; these headings explain its aim, use, title, author, place in study, classification, division, and methods of teaching.