Hegel famously begins the Preface to his Phenomenology of Spirit by declaiming that “everything turns on grasping and expressing the True, not only as Substance but also as Subject.” Although Kierkegaard is, as we have already seen, a great critic of Hegel, this memorable phrase could aptly describe Kierkegaard's own view, except that it must not be applied to “the True,” an Hegelian euphemism for “the Absolute,” which Kierkegaard thinks we humans lack access to, but to the human self. Hegel, as an absolute idealist, thinks that reality as a whole must be understood as a self-conscious unity. The idea is that a philosopher like Spinoza, who saw the whole of reality as one “substance,” is partly right, in that reality is an interconnected substantial whole. However, Spinoza's concept of substance fails to capture the dynamic character of reality as “spirit.” For Hegel a reality that is spirit is dynamic, unfolding, and self-conscious, and the concept of “substance” fails to capture this distinctive character.

Kierkegaard's view of the human self is similar in several respects. As we shall see, Kierkegaard does not want to deny that the self is a substantial reality. However, the unique character of the self is obscured if we think of it merely as a type of “entity” or “substance.” To be a self is to embark on a process in which one becomes something, and there is a sense therefore in which selfhood is something to be achieved.