You can't talk of True Detective’s existential nihilism without talking about Friedrich Nietzsche. Other than his well-known contributions to existentialist philosophy - that of the inherent meaninglessness of life, "God is dead," and "the will to power" - one of Nietzsche's biggest inspirations to the show is his cosmology of Eternal Recurrence, which he discusses in this book as well as in The Gay Science and later in his Notes on Eternal Recurrence.

In The Gay Science, he writes: "This life as you now live it and have lived it, you will have to live once more and innumerable times more; and there will be nothing new in it, but every pain and every joy and every thought and sigh and everything unutterably small or great in your life will have to return to you."

Something similar to this is said by Detective Rustin Cohle (played by Matthew McConaughey) in Episode 5: "Time is a flat circle. Everything we’ve ever done or will do we’re gonna do over and over again."