The main theme of the book is that objectivity and subjectivity are not properties in some way external to the knowing subject, but rather are modes of knowing accessible simultaneously by an individual. In other words, I can look at myself, subjectively, from the inside, and objectively, from the outside. Neither point of view is intrinsically true, but they merely differ in perspective. Because it is necessary to account for human beings from the subject point of view in which they have feelings, motivations, and free will as well as the objective, in which they are material objects acted upon by external forces, ethical and political thought cannot be purely objective (e.g. utilitarian) but must balance both perspectives.