What is Existenialism?
Existentialism is not quite a 'branch' of philosophy but probably better characterised as a 'movement' in philosophy. Existentialism has its roots in the 19th century but didn’t really coalesce into what we think of as existentialism until the early 20th century. At that point, it exploded into the public awareness and then disappeared just as quickly, rapidly becoming the black sheep of the philosophy family that few philosophers wanted to acknowledge, let alone discuss.
Existentialism can be thought of as a very 'gritty' movement, by which I mean concerned with cold, harsh, human realities. This is no 'ivory tower' philosophical search for beauty, truth, or some other such Platonic form, but very much a down to earth, stark, uncompromising take on human life. As such, existentialism can be quite dark and pessimistic. They key term in any definition of existentialism though I think, is human. Existentialism is essentially an honest inquiry into human existence and what that might possibly mean for us, if anything, as human beings. However, that really only gets us halfway. I think whether or not you are an existentialist depends on your answer to that question.
If you come face to face with the brute question of your existence and answer that a good God gives that existence meaning and will reward you with an eternity in heaven singing with angels and playing with puppies (and I seem to have heard something about 72 virgins…) then you are certainly not an existentialist. (Of course there are religious existentialists but most, if not all of them, railed against the Church, contemporary religious opinion, and childish notions of good (God and heaven) and evil (the Devil and hell). On the other hand, if you stare the fact of your existence in the face and answer that there is no higher meaning or purpose, there is no eternal life after death, and your being (such that it is) is absolutely contingent (that is to say, you didn’t have to exist) then you will feel right at home here. So existentialism is basically inquiring into the why’s and wherefore’s of human existence, concluding that there aren’t any readymade answers, and trying to decide where to go from there.
One good way to get a feel for what existentialism is all about is to look at some of the key terms that have emerged:
The absurd: a term that denotes the meaninglessness of existence in the face of the human desire to find meaning and unity
Nausea: the feeling that assails one when one contemplates things in light of the absence of meaning
Anxiety: the feeling that grips one upon first recognising the absurdity of human existence (also called angst/dread)
Despair: the loss of hope of ever finding a source of meaning
Facticity: the brute, unchangeable facts about one’s life that place natural limitations or restrictions on the individual
The individual: central to existentialism. Human existence is something we must each come to grips with as individuals
Death: the ultimate end of human existence and typically not cushioned with consoling views about a transcendent afterlife
Authenticity: an attitude towards life that resolutely accepts the human condition as it is and strives to deal with what that entails
The philosophers most central to existentialism are probably Kierkegaard, Heidegger, Camus, and Sartre, but several other philosophers had existentialist leanings and/or contributed to this movement, most notably, Schopenhauer, Nietzsche, Jaspers, Merleau-Ponty, and Levinas. Existentialism is by no means confined to those who called themselves philosophers though. The unique, visceral subject of existentialism makes it particularly amenable to other mediums including, art, literature, and theatre (Camus and Sartre both wrote novels and composed plays). Two novelists in particular are typically mentioned in any discussion of existentialism; Fyodor Dostoevsky and Franz Kafka, both of whose writings address deeply existentialist themes.