Nihilist: Someone who rejects all theories of morality or religious belief.
Nihilism: This universe is a closed system. Everything is determined. Human beings don’t have real choices, we’re just cogs in a wheel, and the system is going and we’re part of it, and our choices don’t matter, and what we think doesn’t matter. Nothing matters. We’re just cogs in the wheel, to quote a popular rock-and-roll group, “we’re just another brick in the wall.” Nihilism goes on to say that humans are just complex machines; that’s what we are. And we’re part of a bigger and more complex machine. So the idea of true knowledge—it’s meaningless. Ethics are impossible. There is no meaning in life.
Now, as you can imagine, there are very few people in the world who can rest in that. Nietzsche had suggested that there would need to be a race of what he called “super men” who would be able to endure this kind of view of the world until it could be transcended. But there are very few super men and women around who can live with a view of life like this. And so, the secular worldview makers, the philosophers, attempted to come up with their own answers, and one of the very popular answers that was given to Nihilism has been coined as Existentialism.
Remember, we said that
Deism replaced Theism as a worldview in the time of The Enlightenment because it was thought that Theism, on the one hand, was responsible for the internecine wars in Europe, and perhaps a more refined and rational view of God in the world could produce peace and tranquility in human life.
And then,
along behind Deism came Naturalism that says, look, Deism predicates a first cause, a divine maker who made this world like a clock and set it running and then let it go to go and do whatever he was interested in doing, and he no longer interacts in this world. The laws he set in motion are still in motion, so Naturalism says, look, we can take everything that Deism gives and remove the idea of this God who created things, this first cause, and the philosophy works just fine.
And then came a view which said, well, why do you have to assume that this world is rational, and can be made sense of?
So Nihilism came along behind Naturalism. In other words, Nihilism saw all of the presuppositions of Naturalism and said Naturalism’s assumption that we are in a rational world that can be understood and that meaning can be constructed out of is wrong.
http://www.fpcjackson.org/resources/sermons/Worldviews%202004/3b_existent.htm