He existentialism is a philosophical current chasing the knowledge of reality through the immediate experience of one's existence. However, a precise or exact theory that clearly defines this concept has not been developed.

What is clear is that this movement of the philosophy highlights the individual human being as creator of the meaning of his life. The temporality of the subject, its concrete existence in the world , is what constitutes being and not a supposed more abstract essence.
Existentialists do not believe that the individual is a part of a whole, but that each human being is a free integrity in itself. The existence of a person is what defines your essence and not a general human condition.
In other words, the human being exists since he is capable of generating any type of thought. Thought makes the person free: without freedom, there is no existence.
This same freedom makes the individual a responsible being for his actions. There is, therefore, a ethics of the individual responsibility . The person must take charge of the acts he performs in the exercise of his freedom.
Emergence of this thought
This term was the result of an intense philosophical work developed between the nineteenth and twentieth centuries; in a clear search for the reason for existence from the individuality, emotions, actions and responsibility of each individual.
It is considered as father of existentialism to the philosopher Soren Kierkegaard. It was he who determined that each individual is the one who must find meaning in their existence. And he added that the greatest responsibility of the human being lies in living his own life in a passionate and sincere way, despite the thousand obstacles that may arise.
Anyway, the term was not coined until the 40s and those who did were the French Jean-Paul Sartre (1905 -1980 ) and Albert camus (1913 -1960 ). Considered today as the maximum exponents of existentialism .
As explained by Sartre himself existentialism is a human way of understanding existence. Subsequently, thinkers from earlier times such as Hedegger, Nietzche or Kierkegaard himself were included in this ideology.
This current can be divided into various schools; Among them we can highlight: theistic existentialism (reflects on the existence of God and the Spirit), the atheist existentialism (denies the divine) and the agnostic existentialism (considers that the existence of God is irrelevant to human existence).
Existentialism in literature
In literature, surely the maximum allies of this line of thinking were Fiódor Dostoyevski and Franz Kafka.
Among Dostoyevsky's works we could mention "Memories of the subsoil" as a clear existentialist treaty. It presents the life of a man who feels outside his group, unable to fit into society and make sense of its existence. Another work by this author that could be nominated as existentialist is "Crime and punishment."
In Kafka's work there are also several characters that allow this author's ideology to be located close to Dostoyevsky's. Most of them are beings surreal and desperate They find no meaning in breathing every day and they live doomed to an absurd system that represses them and does not allow them to be happy. His fundamental novels "The Metamorphosis" and "The process" are considered two magnificent works within existentialist literature .
It is worth mentioning that he himself Sartre also wrote a novel, entitled "The nausea" that reflects the fundamental ideas of this current. It is recommended as a material to approach complicated philosophical reasoning. It is also a reference work that has inspired many post-French authors, such as Philip K. Dick or Chuck Palahniuk.