In his book The Sickness Unto Death Kierkegaard defines the self as:

“Man is spirit. But what is spirit? Spirit is the self. But what is the self? The self is a relation which relates itself to its own self, or it is that in the relation which relates itself to its own self; the self is not a relation, but that the relation relates itself to its own self. Man is a synthesis of the infinite and the finite, of the temporal and the eternal, of freedom and necessity, in short, a synthesis. A synthesis is a relation between two [components]. So regarded, man is not yet a self. In the relationship between two, the relation is the third as a negative unity, and the two relate themselves to the relation, and in the relation to the

Some topics in this essay:
Death Kierkegaard, Possibility KPA, Study Self, Necessity Possibility, Kierkegaard’s Pseudonymous, Anxiety Kierkegaard, Unto Death, Philosophical Fragments, Dread Kierkegaard, Soren Kierkegaard, eternal temporal, human existence, relation relates own, relation relates, self self, relates own, self relation, temporal eternal, relation relation, infinite finite, own self, relates own self, sickness unto death, eternal freedom necessity, related infinite finite,