I’d be willing to wager that most educated persons if asked to name the father of existentialism would mention Jean-Paul Sartre. That my be true technically since it was he who coined and popularized the existentialist philosophy of the 20th century, but that title really belongs to a philosopher of the preceding century who, without giving it a label, had already conceived and developed the idea of existentialism.

That philosopher was Soren Kierkegaard (1813-1855); born in Copenhagen, the youngest of seven children, five of whom together with his mother had died by the time he was twenty one. This may be one of the factors which gave his personality a pervasive tone of reflective romantic melancholy and it may have influenced his decision not to marry and call off his engagement with Regina. He himself only lived to 42, yet he has left a mark on perennial Western philosophy which is still ongoing.

Kierkegaard early work On the Concept of Irony was a masterful sustained criticism of the philosophy of Hegel. In it he attempts to restore ontological prominence to the individual which had been undervalued and rendered nearly irrelevant by an excessive concern with the whole and the species as seen in the philosophies of Spinoza, Hegel and Marx. It was this pervasive concern for the individual that renders his philosophy existential. There is in fact in Kierkegaard’s philosophy a strict nexus between truth and the subjectivity of the individual. It is one of his recurrent themes: the importance of subjectivity as it relates to objective truths.

In his Concluding Unscientific Postscript to Philosophical Fragments he argues hat "subjectivity is truth" and "truth is subjectivity." What he means by this is that most essentially, truth is not just a matter of discovering objective facts. Those are important, but there is a second and more crucial element of truth, which involves how one relates oneself to those objective facts. Since how one acts is, from the ethical perspective, more important than any matter of fact, truth is to be found in subjectivity rather than objectivity.

Kierkegaard’s other best known works are Either/Or (1843) wherein Kierkegaard distinguished three modes of existence: the “aesthetic,” the “ethical,” and the “religious,” soon fallowed by Repetition, characterized by a concern with the ethical mode of existence: the story of a young man (obviously autobiographical) who is in love but who cannot bring himself to commit to marriage because he fears the ethical commitment that such a status requires, the exclusive dedication to one person; Fear and Trembling (1843) which illustrates the biblical story of Abraham and Isaac and describes the conflict between the ethical mode of existence with its conception of normal moral behavior, and the religious mode; The Concept of Anxiety (1844) which discusses the concept of dread or what currently we call “angst” caused by the individual’s awareness of his freedom of action with nothing to guide him in making his choices.

Let us look in more details what makes Kierkegaard’s philosophy existential. Perhaps this famous epigram of Kierkegaard already suggests its existentialism: “the conclusions of passion are the only reliable ones; what our age lacks is not reflection but passion.” Like Vico before him and Levinas after him, Kierkegaard is suggesting that the whole history of thought may have been preoccupied with the wrong concerns. Beginning with the Greeks, philosophy has been mainly focused on architectonic metaphysical rational schemes which exalt reason or experience as a way of making sense of the world.

None of these systems, as far as Kierkegaard is concerned, take into account the fundamental human condition characterized by the necessity to make constant decisions. In other words, choice is our constant companion and heavy burden. In his Journals Kierkegaard complains that “what I really lack is to be clear in my mind what I am to do, not what I am to know…the thing is to find a truth which is true for me, to find the idea for which I can live and die.” This burden of decision making is a recurrent theme in all existentialist philosophy.

Eventually Kierkegaard gives us a hint of a possible answer, one that works at least for him. That answer is religious belief. But this has little to do with the bourgeoisie State Danish Church of his times which he finds incompatible with his own Christian beliefs and in fact he considers the very antithesis of Christianity: a sort of going through the motions, attending Church, following neatly ordained ethical precepts, reciting scripture. All of that is sterile and has nothing to do with religious life unless it involves a personal and direct confrontation with the divine.

So, what exactly is religious belief for Kierkegaard? It is certainly not its caricature as exemplified in the writings of Karl Marx. For Kierkegaard religious belief is not a matter of reason but one of passion. This echoes Pascal’s dictum: the heart has reasons that reason knows not. For Kierkegaard, reason can only undermine faith, never justify it. He is convinced that even rationalistic proofs of the existence of God as found in Aquinas’s Summa, have precious little to do with belief in God. Belief in God is not an intellectual exercise but a passionate personal choice.

What authentic belief requires is an authentic force from within, a “leap of faith,” but without the guidance of reason to reassure us that we are doing what is “right” or “true.” Those reassurances, exactly because they are a matter of commons sense and rational reflection, remove the need for faith in God’s existence. The god of the philosophers utilized to underpin their thinking, from Plato and Aristotle, all the way to Spinoza, Descartes and Leibniz is not the living God of Abraham, Isaac and Jacob, the God with whom Jacob struggles all night till he is granted a new name, Israel. Indeed, the heart has reasons that reason know not.