Is despair a merit or a defect? Purely dialectically it is both. If one were to think of despair only in the abstract, without reference to some particular despairer, one would have to say it is an enormous merit. The possibility of this sickness is man’s advantage over the beast, and it is an advantage which characterizes him quite otherwise than the upright posture, for it bespeaks the infinite erectness or loftiness of his being spirit. The possibility of this sickness is man’s advantage over the beast; to be aware of this sickness is the Christian’s advantage over natural man; to be cured of this sickness is the Christian’s blessedness. — Anti-Climacus, The Sickness Unto Death p. 45
Most emphatically in The Sickness Unto Death, Kierkegaard's author argues that the human self is a composition of various aspects that must be brought into conscious balance: the finite, the infinite, a consciousness of the "relationship of the two to itself," and a consciousness of "the power that posited" the self. The finite (limitations such as those imposed by one's body or one's concrete circumstances) and the infinite (those capacities that free us from limitations such as imagination) always exist in a state of tension. That tension between two aspects of the "self" that must be brought into balance. When the self is out of balance, i.e., has the wrong understanding of who it is because it conceives itself too much in terms of its own limiting circumstances (and thus fails to recognize its own freedom to determine what it will be) or too much in terms of what it would like to be, (thus ignoring its own circumstances), the person is in a state of Despair. Notably, Anti-Climacus says one can be in despair even if one feels perfectly happy. Despair is not just an emotion, in a deeper sense it is the loss of self, i.e., it describes the state when one has the wrong conception of oneself. In Either/Or, A and Judge William each has one epistolary novel in two volumes. The A is an aesthete well aware that he can use the power of interpretation to define who he is and what he takes to be valuable. He knows he can shape and reshape his own self-identity. Nothing binds him to his relationships. Nothing binds him to his past actions. In the end though, he also knows he lacks a consistent understanding of who he is. He lacks a self that resists his own power of reinterpretation. His older friend Judge William, argues that a deeper concept of selfhood is discovered as one commits to one's actions, and takes ownership of the past and present. A concept of oneself, as this particular human being, begins to take form in one's own consciousness. Another perspective, one in which an individual can find some measure of freedom from despair, is available for the person with religious "faith." This attunes the individual so that he or she can recognize what has always been there: a self to be realized within the circumstances it finds itself right now, i.e., this inner attunement brings about a sort of synthesis between the infinite and the finite. In Fear and Trembling, Johannes de Silentio argues that the choice of Abraham to obey the private, unethical, commandment of God to sacrifice his son reveals what faith entails: he directs his consciousness absolutely toward "the absolute" rather than the merely ethical, i.e., he practices an inner spirituality that seeks to be "before god" rather than seeking to understand himself as an ethically upright person. His God requires more than being good, he demands that he seek out an inner commitment to him. If Abraham were to blithely obey, his actions would have no meaning. It is only when he acts with fear and trembling that he demonstrates a full awareness that murdering a son is absolutely wrong, ethically speaking.
Despair has several specific levels that a person can find themselves, each one further in despair than the last as laid out in The Sickness Unto Death.
The first level is "The despair that is ignorant of being despair or the despairing ignorance of having a self and an eternal self." Essentially this level is one which has the wrong conception of what a self is, i.e., is ignorant of how to realize the self one already potentially is. In this sense, the person does not recognize his own despair because he often measures the success of his life based on whether he himself judges himself to be happy. Regardless of whether you know you are in despair or not, Kierkegaard asserts, you can still be in that state. He notes that this is the most common in the world.
The next level of despair is "The despair that is conscious of being despair and therefore is conscious of having a self in which there is something eternal and then either in despair does not will to be itself or in despair wills to be itself." The first form of this conscious despair is "In despair not to will or want to be oneself." This becomes further subdivided into three categories: the one already mentioned, the despair not to will to be a self, and lowest, the despair to wish for a new self. These three divisions are mostly the self-worth the person has and the amount to which they understand their own despair. The despair to not be oneself is pretty straightforward. A person sees themself as unworthy and as such does not see themself as worthy before something they do not understand. The despair not to be a self is deeper, because to not wish to be a self is to wish to not have a relation to God or at the very least see one's relation to God as unworthy, and thus shrink from it. The lowest form of this group, however, is the desire to be a new self. This is logically the deepest form as it assumes the deepest understanding of one's despair. Once in despair, without a complete relation to God one will always be in despair, so to be in this level one understands the permanence of the despair. The despair in this group arises from the nature of sensate things and physical desires. These three sub groups are also grouped under the heading "Despair over the earthly."
The second level of conscious despair under the heading "Despair over the eternal." Someone in this level views themself in light of their own weakness. Unlike in the upper level, this weakness is understood and as such, instead of turning to faith and humbling oneself before God, they despair in their own weakness and unworthiness. In this sense, they despair over the eternal and refuse to be comforted by the light of God.
The last and lowest form of despair is the desire "In despair to will to be oneself." This last form of despair is also referred to by Kierkegaard as "demonic despair" (Note that the term demonic is used in the Classical Greek Sense, not the modern sense). In this form of despair, the individual finds him or herself in despair, understands they are in despair, seeks some way to alleviate it, and yet no help is forthcoming. As a result, the self becomes hardened against any form of help and "Even if God in heaven and all the angels offered him aid, he would not want it." At this level of despair the individual revels in their own despair and sees their own pain as lifting them up above the base nature of other humans who do not find themselves in this state. This is the least common form of despair and Kierkegaard claims it is mostly found in true poets. This despair can also be called the despair of defiance, as it is the despair that strikes out against all that is eternal. One last note is that as one travels further down the forms of despair, the number of people in each group becomes fewer.