You know the type. The Existentialist protagonist is a bored, angry, alienated, cynical, profane, violent, and angst-filled teenager, who sees through other people's phoniness with absolute clarity, who often experiments with drugs and sex, and who basically is experiencing an extreme crisis of self-identity. His future is uncertain. While this was scandalous in the 1950s, especially when depicted in the 1951 novel The Catcher in the Rye, what was once a rare example of problematic psychology in the Enlightenment Age is now unfortunately the norm.
A discussion forum on Walker Percy's book Lost in the Cosmos, was quite illuminating. This book identifies the core problem of today's society as an existential one, where people lose sense of self and especially their relationship with others and with God, leading to our culture's embrace of violence and disordered sexuality. One commenter stated that reading the old books on Existentialism, like Percy's, is like reading a radical book which denounces geocentrism: so what? The fact of 'existential angst' is now well-recognized. Nearly everyone under a certain age, he claims, is in an existential crisis and knows it, and credits the mass media and education system for this.
Existentialism in film is well established, with well-known titles including: High Noon, The Graduate, One Flew Over the Cuckoo's Nest, Taxi Driver, The Matrix, Fight Club, Garden State, A Clockwork Orange, Donnie Darko, Cool Hand Luke, American Beauty, Apocalypse Now, Blade Runner, and the films of Woody Allen, François Truffaut, and Jean-Luc Godard. And many others. Life, as we have seen, does imitate art, for the crisis of identity for most was preceded by the popular culture.
The key attribute of someone in an existential crisis is overwhelming anxiety, and an existentialist seeks to embrace this anxiety or angst by a free search for 'meaning' or 'authenticity'. But we ought to recall the words from the Mass of Paul VI: Deliver us, Lord, from every evil, and grant us peace in our day. In your mercy keep us free from sin and protect us from all anxiety as we wait in joyful hope for the coming of our Savior, Jesus Christ. Or in other words, anxiety is due to our fallen nature and is not to be embraced.
Modern Existentialism was founded by the Protestant philosopher Søren Kierkegaard, and this philosophical movement has since split into numerous denominations, with various thinkers — atheist or Christian — jettisoning one particular aspect of the theory or another to suit their taste. Like the huge Enlightenment armies doing battle against each other, the modern philosophies also conflict with each other, with supremacy being gained through brute force, and not because they are shown to be true.
Existentialism was rejected by Pope Pius XII in his encyclical Humani Generis, dating from 1950. He instead called for a return to the far richer and more universal philosophy of Saint Thomas Aquinas. As it turns out, Aquinas also has quite a bit to say about existence and the self, but no one makes films about it.