In Chapter 2 I introduced Kierkegaard's view that human lives can be usefully categorized as aesthetic, ethical, or religious, the well-known view of the “three stages on life's way.” One might say that these represent different forms of inwardness or subjectivity, different configurations of caring and passion that give particular shape to human lives. In referring to these forms of human life as “stages,” Kierkegaard means to speak about human existence in a developmental fashion, indicating that in some sense it is natural for human beings to begin as children in the aesthetic stage and progress to the ethical and eventually the religious stages.

However, Kierkegaard also refers to the aesthetic, ethical, and religious as “spheres of existence.” So a first question is how they can be both stages and spheres. The answer lies in recalling the spiritual character of human selfhood. Human persons are partially self-determining beings who freely participate in their own development. Although Kierkegaard thinks that human persons are intended by their Creator to develop from the aesthetic to the ethical and the religious, and in that sense such development is “natural,” spiritual development is never inevitable or automatic. Becoming spiritually mature is not at all like acquiring facial hair or wisdom teeth. Rather a person can become “fixated” (to use contemporary psychological jargon) in a particular stage, and if the person becomes aware of this and aware of the higher possibilities he or she is refusing, then that stage really has become an existentially-chosen sphere of existence.