Søren Kierkegaard
1813 CE – 1855 CE · 19th Century Era
“Truth is subjective; authentic existence demands passionate commitment in the face of uncertainty.”
Biography
Writing under numerous pseudonyms, Kierkegaard attacked Hegel's system for abstracting away the anguish and passion of individual existence. He insisted that the most important truths, about how to live, what to believe, who to become, cannot be captured in systems but must be personally lived and chosen.
Major Works
Notable Quotes
“Life can only be understood backwards; but it must be lived forwards.”
— Journals
“Anxiety is the dizziness of freedom.”
— The Concept of Anxiety
“The most common form of despair is not being who you are.”
— The Sickness Unto Death
“To dare is to lose one's footing momentarily. Not to dare is to lose oneself.”
— Either/Or
“Faith is the highest passion in a human being.”
— Fear and Trembling
“Once you label me you negate me.”
— Journals
Key Arguments
Click “Philosophy 101” to read the full exploration of each argument.
The Leap of Faith
Rational argument cannot bridge the gap to religious faith. One must make a passionate, personal leap beyond reason, risking everything on what cannot be proven.
Why it matters: Challenged the Enlightenment's confidence in pure reason and inaugurated existentialism.
The Three Stages of Existence
Human life can be lived at three levels. The aesthetic stage pursues pleasure, novelty, and sensation, but leads inevitably to boredom and despair. The ethical stage commits to duty, responsibility, and universal moral rules, but can become rigid and self-righteous. The religious stage transcends both through a personal relationship with God that demands absolute commitment and cannot be justified by reason or ethics. Each stage is a complete worldview, and the transition between them requires not argument but a leap, a fundamental reorientation of the self.
Why it matters: Anticipated psychology's interest in stages of moral and personal growth, and it challenged the assumption that philosophy could provide a single rational framework for all of human life.
Anxiety and Authentic Selfhood
Anxiety is not a weakness or a disorder, it is the inescapable consequence of human freedom. We are anxious because we face real choices that define who we are, and no rule or system can make those choices for us. The temptation is to flee from anxiety into conformity, to do what 'one does,' to believe what 'one believes,' to vanish into the crowd. Authentic selfhood means facing the anxiety of freedom and choosing to become a specific individual, not a copy.
Why it matters: Laid the foundation for existentialism's central themes decades before Heidegger and Sartre. Kierkegaard's analysis of anxiety, authenticity, and the flight into conformity directly shaped Heidegger's concept of 'das Man' and Sartre's 'bad faith,' and anticipated modern psychology's understanding of existential anxiety.
Frequently Asked Questions
Lasting Influence
Originated the existentialist tradition. Influenced Heidegger, Sartre, Camus, Tillich, and modern theology.
Related Philosophers
St. Augustine
354 CE – 430 CE
God is the source of all truth; evil is merely the absence of good.
Blaise Pascal
1623 CE – 1662 CE
The heart has its reasons which reason knows nothing of.
Plato
428 BCE – 348 BCE
Reality consists of eternal, perfect Forms: the physical world is their shadow.
Aristotle
384 BCE – 322 BCE
Knowledge comes from empirical observation; virtue is the golden mean between extremes.
Epicurus
341 BCE – 270 BCE
Pleasure, understood as the absence of pain and anxiety, is the highest good.
Maimonides
1138 CE – 1204 CE
Reason and revelation are harmonious; God is best understood through what He is not.
Your Reading Path
The Companion Guide
Seven eras of philosophy in one volume — reading lists, key terms, journal prompts · $19.99