Mainstream Philosophy is an extremely interesting and intricate subject that builds on itself constantly, you can think of it as a science. The first three Philosophers were Socrates, who mentored Plato, and Plato brought up Aristotle, all of them influenced the way Philosophers think even to this day. Jumping to the next group of prominent philosophers who have affected the ideas we’ll be analyzing today: We’ve got Descartes who stood in stark contrast to Locke, then Barkeley who critiqued Locke’s ideas; all of whom led to Hume’s writing on epistemology. Hume’s epistemology served as Kierkegaard and Sartre’s basis for knowledge. Sartre then took Hume’s skepticism/ epistemology and led it to its logical conclusion, Existentialism. While everyone disagrees with these Philosophers on different fundamental ideas, all of them have had a significant impact on our world, and all of their concepts are worth considering, critiquing, or adopting. Today, I’ll make a major critique on both Kirkegaard and Sartre, with one simple idea. To adopt the idea of a Godless creation is just as much a leap of faith, if not a bigger one, than to believe in a God; to come to any metaphysical conclusion is a leap of faith for the Philosopher who has adopted an epistemology similar to Hume’s (ref. Hume’s Radical Epistemology and D.H and Western Epistemology), this major oversight has led to a wide acceptance of Sartre’s existentialism in our western culture.

A short summary of the ideas of both Kirkegaard and Sartre. Kirkegaard believed that to live a meaningful life we must believe in a God, although he did not think belief in a God could be rational, so he proposed the Leap of Faith idea. We leap into the belief of God and accept it as our presupposition when dealing with life (ref. Kierkegaard's Fear and Trembling) . Though I disagree with his conclusion on belief in a God being fundamentally irrational, because of apologetics and differing epistemology, I’ll go with his version of this idea for the sake of argument. Sartre was an extreme Existentialist thinker, he believed there was no God in our world and thus no meaning, no morality, and no purpose. All we can do is add meaning to our own lives in an attempt to not end ourselves (ref. Sartre’s Existentialism is a Humanism). The ideas have been summarized but it is the basics of their reasoning and conclusions.

My point is this, Sartre’s presupposition, and almost every other existentialist’s presupposition, is that there is no God, yet they claim this is a rational philosophy. Sartre makes this extreme assumption and then bases an entire philosophical ideology on it, and this has made a massive negative impact on our modern culture. To accept the premise that there is no God, is a Leap of Faith just the same as Kirkegaard put it when describing belief in any God, that is unreasonable and baseless. If Sartre truly holds to the epistemology similar to Hume’s, which he claims to, then he believes that if we wish to truly know anything we must question everything and it must be supported by evidence that is both rational and tangible. In that case Sartre must believe Kierkegaard is right to say that if we hold beliefs about anything transcendental, or anything that is outside of what we can directly experience, we must take a leap of faith into those beliefs; of course, Kierkegaard was mainly referring to Christianity when he said this, but this is correct about every metaphysical/ transcendental belief. This is either a massive oversight on Sartre’s part or a willful, undisclosed, leap of faith into atheism; either way, it completely dismantles Sartre’s ideology.

Kierkegaard was correct when he said it is a leap of faith to believe in God, if you hold to the same epistemology as Hume. You simply cannot come to any other conclusion within their epistemology. However, Kierkegaard did not apply this in the opposite direction, which is atheism, when he should have. Sartre’s philosophy, and version of existentialism as a whole, is based on a presupposition which lacks any significant evidence, their evidence is actually a perceived lack of evidence for theism. I’d encourage modern day thinkers to challenge this presupposition just like we would any other idea, study classical and presuppositional apologetics along with the large variety of arguments from atheists. After all, there is no question more important than this: Is there a God?