 In Book Ε, Aristotle adds another description to the study of the causes and principles of beings qua beings. Whereas natural science studies objects that are material and subject to change, and mathematics studies objects that although not subject to change are nevertheless not separate from (i.e., independent of) matter, there is still room for a science that studies things (if indeed there are any) that are eternal, not subject to change, and independent of matter. Such a science, he says, is theology, and this is the “first” and “highest” science. Aristotle’s identification of theology, so conceived, with the study of being qua being has proved challenging to his interpreters. We discuss this identification in  Section 14  below.