To this day, existentialism still preoccupies those working in philosophy, and even literature and art, and we would not be exaggerating if we say that it is the same as people of religion. Existentialism is an issue that identifies with and touches upon man and his dialectical existence. It is impossible - therefore - for the human mind to stop taking and abusing it.
In his book (Existentialist Doctrines from Kierkegaard to Jean-Paul Sartre), Regis Jolivet intends to shed light on existentialism, its development over time, and what each of the philosophers who belonged to existentialism brought to it, until they developed their own versions of it, so we have multiple philosophical existentialist doctrines. Not one sect. The book studies: Kierkegaard, Heidegger, Sartre, Karl Jespers, and Gabriel Marcel.