Naturalism and Nihilism

This is a slightly revised version of a post which appeared on VP on 11/8/13.

French existential philosopher Jean Paul Sartre once wrote that existentialism is nothing else but an attempt to take atheism to its logical conclusion. Many atheists are reluctant to do this because they can't live consistently with their belief that man is all alone in the cosmos.

Some there are, though, who call upon their fellow non-theists to face up to the gloomy entailments of the belief that nature is all there is. Alex Rosenberg and Joel Marks are two who seek to face squarely the logic of their unbelief. Another example is a commenter at Uncommon Descent who lays out clearly and with no sugar-coating what one should believe if one also embraces atheism, as he (or she) does.

He/she writes:

I’m a nihilist because it shows reality. If there is no higher power, then everything humanity holds dear was constructed by humanity and therefore not real.

Thus there is:

• No objective, absolute, inherent meaning in life or the universe
• No objective, absolute, inherent purpose in life or the universe
• No objective, absolute, inherent value in life or the universe
• No objective, absolute, inherent morality in life or the universe. No good, no evil, no right, no wrong
• No objective, absolute, inherent truth in life or the universe
• No objective, absolute, inherent knowledge in life or the universe
• No objective, absolute, inherent logic in life or the universe

There's more:

• We are the cobbled together Frankensteins of billions of years of trial and error
• We have no free-will, mind, consciousness, rationality or reason. They are illusions and [the notions of] personhood, identity and humanity are not real.
• The emotions we express are just chemicals in our brain. The very things we seek in life like happiness, peace, contentment, joy are just chemicals reducing us to nothing more than chemical addicts.
• We are no more important than other animals. A dog is a rat is a pig is a boy.
• There is no afterlife. Once we die, we fade from existence and all our memories, experiences, knowledge etc goes with it. In time, we are forgotten.
• All the things we do in life are just for survival. Learning, loving, seeking, being positive, eating, relating, having fun are created for the sake of ignoring the real reason we are here and that’s to live as long as we can.
• There is no help coming to save humanity as a species or as individuals. We are all alone and on our own. If you can’t survive, you die.

The reader might wonder why anyone would embrace such a melancholy set of beliefs, but if the only alternative to nihilism is to accept that there's a God, then nihilism, as depressing, hopeless, and bleak as it may be, will still be more appealing to a lot of people than the theistic alternative. The writer might reply that atheism is true and we should therefore have the courage to accept its consequences, but why think atheism is true? Could one not reason that it's far more probable that the above list of consequences is not true than that it is true? And if the above consequences are not true then, since they're entailed by atheism, atheism is not true.