When we think of modern existentialism and the individual who is free to create to his own identity apart from socially accepted norms of human development and thought, we may think of founders like Sartre, Nietzsche, Freud, and even Simone de Beauvoir because they rejected this idea of humanism and the value of humanity based on Biblical dogma.
We tend to forget about Soren Kierkegaard (one of my favourite philosophers) who was the first to propose any existential notion of the individual: Truth is Subjectivity and Doubt is conquered by faith, just as it is faith that has brought doubt into the world, as well as his “leap of faith” theory.
Where Sartre, Nietzsche, and even Freud have simply discounted or ignored the gap between empirical observations and the notion of “God” as irrational, Soren Kierkegaard has stressed the importance of the individual to find such truths for oneself and taking alternate routes from scientific methodology to discover such facets of the human identity. Kierkegaard’s belief in the superrational (not irrational) is an acceptance of Socrates statement: All I know is that I know nothing. Existentialism does not necessarily imply nihilism (we are born to die) or that we are burdened with the (re)fabrication of our existence, but simply to question our purpose and to examine the essence of the cosmos as both unfathomable and beyond one method of analysis. Spiritual, emotional, or even mental experience is neither quantifiable nor fourth dimensional, but transcendent and requiring its own “gauges”. The search for certainty is not futile, but passionate and distinctly human.