Philosophy Ph.D Paul J. Ennis’s analysis of Rust’s comparison of life to a nightmare:

I see this strain throughout [Rust’s] monologues that life is a trap, a dream, or a program. Once you grasp that, and truly believe it, then you cannot help but see the self as akin to being trapped in a kind of nightmarish loop. In many ways, the self is the micro-scale of this nightmare and time is the macro-scale that he also touches on in terms of a ceaseless loop. There are some tensions between these positions, but common to both is the idea that we are puppets at the mercy of wider forces.

A locked room mystery is a sub-genre of mystery fiction where a crime is committed in a manner that appears impossible. But it is also an interesting metaphor for our minds, and the way that we self-regulate the way we think.

So the “locked room” refers to the type of mystery that seems, on the surface, insoluble. And that definition of a locked room translates into Cohle’s metaphysical digressions. Which is that your life is what you experience, and more than that, what you think of what you’ve experienced. And all that takes place inside your head, and your head is a locked room"

– Nic Pizzolatto

The “stone tablet” is a direct reference to the 2 stone tablets containing the 10 Commandments that Moses came down from the mountain with.

Which obviously relates to their entire discussion as the commandments are more or less rules to abide by to make civilization a generally decent place; Rust implores that a person shouldn’t have to have something spelled out for them to know right from wrong.

Rust often speaks in strictly physical terms as a coping mechanism; he doesn’t want things to have deeper meaning. Earth has always been viewed as a special planet to humans; it is the only place they would be able to survive and was once considered the center of the universe.

But to Rust it is just a giant rock that contains the right compounds to ensure these “puppets” don’t croak; he does not see a difference between the earth and the uninhabited moon.