The individual is naturally made up of a conglomerate of cumbersome and distressing emotions, such as fear and anguish. It is in senseless circumstances that humans are capable of experiencing inherent fear. In moments of fear, people are able to apply existentialist thinking, because it is through fear that people decide to act. Existentialism is a philosophical theory governed by authenticity, that is, according to which a person's existence is determined through acts of their own will ("existentialism"). Throughout the literature, existentialist theorists are able to portray the capacity that inherent fear plays on the human condition. Fear is the primary reason humans choose to act. People are biologically programmed to respond to fear-inducing situations. Human beings act driven by emotions, motivating them to act. An emotion such as fear is stimulated through the thalamus, which then sends a signal to the cerebral cortex that produces feelings associated with events, be they feelings related to sadness or joy (Klein, Stephen B., and Michael Thorne 424). Human beings, all over the world, suffer from the biological and spontaneous reactions that fear, or rather most emotions, create. No one is excluded from the unconscious actions that the mind establishes. It is not only emotion that allows the mind to control the will, but it is through feelings that the individual truly detaches himself from the subconscious need to integrate into society and discover himself in a world where existence itself is a questionable idea. . experiencing emotions, emotions lead to feelings which are the true thoughts that motivate the individual person to act beyond the capabilities of their emotional state. The people are, in... middle of paper... EdBeckett, Samuel. Waiting for Godot. New York. 1954. Collin, Catherine. The Psychology Book: Big Ideas Simply Explained. New York. DK Publishing.Crowell, Steven. "Existentialism". Stanford University. August 23, 2004. Stanford University. November 15, 2013. .Gardiner, Patrick. Kierkegaard: a very brief introduction. Oxford. Oxford University Publications. 1988. Klein, Stephen B. and Michael Thorne. Biological perspective. New York. Macmillan. 2006.Marino, Gordon D. Fundamental Writings of Existentialism. New York. Modern library. 2004.Nietzsche, Friedrich. Fundamental writings of Nietzsche. New York. Modern library. 1968.Sartre, Jean-Paul. “Existentialism is a humanism 1946”. February 1998. Meridian Publishing House. 15 November 2013. .Sartre, Jean-Paul. Nausea. New York. New Directions Publishing Company. 1964.