Hi there, I'm Jason Gots and you're listening to Think Again, a Big Think podcast.

I'm underground as I write this one day before taping the conversation you're about to hear,

speeding through New York City subway tunnels that aren't all that ancient, but whose darkness

and rats and crumbling,

esoteric infrastructure holds fear and fascination enough for anyone who contemplates them.

Waking up this morning, notice how you wake up, not down, I felt my already barely remembered

dreams sliding off of me in layers like leaves or hands, and the longing to submit to

those hands and slide back down

underground into the caverns of sleep. My guest today, Robert McFarlane, has dug deeper than I

could ever hope to into the meanings and magnetism of the underworld, tunnels, caves, sinkholes,

and the living fungal earth of our world and our imaginations. At one point in his

new book, Underland, he brings up the fact that to a neutrino, our solid physical world is just a

mesh. Mount Everest is a wide gauge net it can pass easily through. In McFarlane's writing, the layers of the

world are transparent, overlapping, always already present. He's

often called a Nietzsche writer, but that's a poor proxy for what he actually is, a philosopher,

poet with the gift of sight in the darkness, whose penetrating vision turns the world inside out.

Welcome to think again, Robert.

Well, thank you for that introduction. I can only disappoint your listeners now.

I feel like in trying to figure out where to start this conversation, I'm having what must

be the same problem or challenge that you must deal with in writing a book like this.

In the book, I mean there are specific

adventures that you go on but there are so many kind of lucid metaphorical

...