Published in 1846, Concluding Unscientific Postscript to the Philosophical Fragments is one of the major works of the Danish philosopher and theologian Søren Kierkegaard. The book is so named because Kierkegaard intended it as a sequel to his 1844 work Philosophical Fragments, although the Postscript is more than six times longer than the Fragments. The word “unscientific” is an ironic allusion to rationalistic philosophy, particularly that of Georg Wilhelm Friedrich Hegel.

Hegel’s philosophy—known as Hegelianism—held that “the rational alone is real.” The Postscript has become famous for its contrary assertion that “truth is subjective.” Writing under the pseudonym Johannes Climacus, Kierkegaard asserts that truth is not something that one possesses but rather something that one lives. Each individual must pursue, search for, and engage with truth: Truth is truth for an existing human subject. Thus, Kierkegaard argues for the necessity of being a “subjective thinker.”

In contrast to this is the objective thinker as conceived in Hegelian philosophy. While subjective thinkers ask “how,” objective thinkers concentrate on “what.” Truth for them does not require inner reflection, nor is it a part of them. It exists outside as a separate, indifferent thing. For Hegelians, truth is truth regardless of what one thinks; thus, thought and the existence of individual human beings become irrelevant to it.

By contrast, subjective thinkers use thought to explore the unknown and so seek to understand reality. Not only are subjective thinkers actively aware that they exist, but they come to see that individuals are the only things that do exist. Existence itself is a subjective experience. Properly speaking, there is no “humanity”—only individual humans. A crowd is an abstract idea, but a person is rooted in reality. Yet because individuals are constantly in flux, they are always probing for truth; thus, they are constantly learning, or “becoming.” Since the theory of objective truth does not allow for this ongoing transformation, Hegelianism (which Kierkegaard calls “the System” or “speculative philosophy”) cannot accurately describe reality. It remains static and abstract and does not take individual human experience into account.

Thought results in action, so for subjective thinkers their decisions determine their truth. They possess the decision—what Kierkegaard calls the “either/or”—and this is the greatness of each human being. For Hegelians, an individual’s decisions matter little because these decisions do not affect objective truth. Thus, in Hegelianism, human history tends to become the play of impersonal forces.

According to Kierkegaard, Hegelian thought negatively influences society by making people more interested in abstract theories than in living their lives in a meaningful way. More specifically, as a Christian thinker, Kierkegaard sees Hegelianism as damaging to faith, as it destroys a sense of religious mystery and separates the believer from a personal relationship with God. In Kierkegaard’s view, without passion and a strong inner life, we are not truly existing. Kierkegaard’s ultimate purpose in the Postscript is to define how the Christian can relate to the truth of his religion—and the eternal happiness it promises—in a way that befits the strong personal claim that Christianity has on him. The Postscript is therefore a work of religious philosophy. In presenting his argument, Kierkegaard employs a variety of tones and literary devices, including irony, satire, personal narrative, and “indirect communication” through an assumed persona.

This guide refers to the 1941 translation of the Concluding Unscientific Postscript by David F. Swenson and Walter Lowrie.

Summary

Book 1 of the Postscript deals with the “objective problem” of Christianity: Christianity viewed as a historical phenomenon. Although Christianity is certainly rooted in history—the life, death, and resurrection of Jesus and the ministry of the church through the ages—Kierkegaard argues that historical arguments cannot convince one to embrace Christianity because they do not get at the heart of what the religion means for the individual human spirit. To understand Christianity truly, one must adopt not an objective attitude, but a subjective one.

Book 2 deals with the “subjective problem” of Christianity; it is more than three times as long as Book 1 and consists of two parts. In Part 1 Kierkegaard analyzes the thought of G.E. Lessing, presenting the German philosopher as an exemplar of subjective thought. In Part 2 Kierkegaard elaborates on the nature of subjective thought and its implications for religious faith.

“Becoming subjective”—the topic of three of the chapters in Part 2—is a task that everyone who wishes to live as an authentic, thinking human person must perform. The subjective thinker is “passionately interested” in their own eternal happiness—the promise Christianity extends. The subjective thinker never loses sight of the fact that they are themself a person existing in time—in a constant state of becoming—yet oriented to eternity.

Kierkegaard’s discussion of subjective thought culminates in his signature claim, “Subjectivity is truth,” because truth is essentially related to an existing human subject. Subjectivity relates to action, and thus the subjective thinker will make ethical choices rather than abstract intellectualism central to their life.

In the final chapter of Book 2, Kierkegaard tries to make sense of an existential puzzle related to Christianity: how it is that the Christian’s eternal happiness is decided in time and by a relationship to something historical (i.e., the man Jesus Christ). Further complicating this is the fact that the “something historical” is itself a paradox: God, who is eternal, has entered time as a human being. Thus, Christianity involves believing in something rationally absurd. The subjective Christian, like the subjective thinker in general, will embrace this paradox in faith and let it transform their life.

Extending the idea that Christianity embodies paradoxes, Kierkegaard concludes that the Christian’s relationship to eternal happiness is expressed through its opposite: suffering. The consciousness of guilt and sin help to “sharpen” the Christian’s “pathos” and thus intensify their relationship to God and eternal happiness. Such an existential relationship is far deeper and affects the individual far more than objective intellectual processes.