Existensialism shares some similarities with stoicism, maybe that's why I like it. Existensialism is all about freedom. At the heart of freedom is choice and at the hear of choice is action. Action, then, is at the heart of existensialms, just as it is at the heart of human existence. As Sartre says -- "To be is to do".
Yeah yeah, enough bullshit. What is it in my view? Well, similarly to all other philosophies I talk about on this website, things go waaaay deeper than I make them seem. I selectively keep bits and pieces of it, and this will not be any different. Existensialism is all about accepting that there's no meaning to anything, yet we're able to create our own meaning in our minds and that is true enough to make life beautiful to live.
Existentialists are nihilists because they recognize that life is ultimately absurd and full of terrible, inescapable truths. They are anti-nihilist because they recognise that life does in fact have meaning: the meaning each person chooses to give to their own existence. They recognize that each person is free to create themselves and make something worthwhile of themselves by striving against life's difficulties. Life, or rather death, will win in the end, but what matters is the striving, the overcoming, the journey.
In the Myth of Sisyphus, Camus opens saying that the only truly importan philosphical question is that of suicide. He sees that in choosing to live, in refusing the ever-present possiblity of suicide, a person confers value and significance on a life that has no value or significance in itself. In choosing to live his life rather than end it a person takes on responsiblity for his life.
The philosophy goes deep, but Sarte and co. show us that the world, our owrld, is constantly subject to our active interpretation of it. We constantly encounter a world characterize and defined by motives, intentions and attitudes we choose to have and the evaluations we choose to make. The world for each person is a product of the attitude with which he or she approaches it. They argue that the person who chooses to be positive and confident, or at least, genuinely tries to be positive and confident, will encounter a very different world from the person who chooses to be negative and timid.
Another topic I love about existensialism is what Camus calls philosphical suicide. He claims that philosphers like Kierkegaard and Nietzche commit philosphical suicide by arriving at the same conclusions as him, that life has no meaning and then choosing metaphysical or theological explanations as the solution. As opposed to facing it, that it is absurdity. The abusrd is the persistent human demand for sense meeting an unresponsive world, the mere size difference between the human and the universe further exasperates the absurdity.
There's a lot of other stuff they get into. Temporality, being-for-others, authenticity, bad faith, moustaches and salauds, and so on. I find it a little bit funny to be honest, how much meaning and structure they try to give to something they've already accepted as absurd. For me it doesn't quite click, it gets a bit too masturbatory so I'll leae it at that.