Does the brain control you, or are you controlling the brain? I don’t know if I’m in charge of mine.

Karl Pilkington sounds foolish, but he’s onto something. He tells an anecdote about a time when he finished his grocery list and moved on only to be interrupted by a thought that entered his mind suddenly: Apple.

That was weird — who reminded me of that?

The thought of apple just appeared and Karl doesn’t know how. It fell like a raindrop into his mind. This happens to us all the time, but we don’t notice it because we expect it. We think What’s his name again? and then something inside us slips an answer into our grasp: Mark. It’s like shaking a tree until fruit falls out. We don’t give the tree much credit. But Karl was leaving the orchard when the apple came rolling after him.

We talk about the subconscious as a mysterious engine that runs the dreams we soon forget after we wake up. But it’s also there in the day. It hums along softly in the background, chiming in helpfully when we need to remember someone’s name or what produce to buy.

But it’s more than our assistant. It’s our advisor, our consigliere. It’s the source of our gut feelings. Great ideas come from interaction with this humble inner partner, this invisible thinker.

Despite being teased by his buddies for his story about the apple, Karl echoed something the French polymath Poincaré wrote in his essay, Mathematical Creation:

At the moment when I put my foot on the step the idea came to me, without anything in my former thoughts seeming to have paved the way for it.

Like Karl, Poincaré tells stories of answers coming to him when he was no longer considering the question. And he welcomes it. He recognizes his subconscious mind as a vital actor in his work, a shrewd associate that finds a fresh lead while he rests.

Poincaré then concludes something that Karl would’ve been mocked for saying: resting is productive. Not because it reenergizes you for more work, but because it is work. Rest releases the invisible thinker to explore and find what you haven’t noticed yet. You can feel this happening in the shower when novel ideas surface in your mind without prompt. And though we can’t steer our ambient thought, “ambient thought”, we can set the direction. tell it what to think about. As Don Draper of Mad Men tells his protégé:

> Peggy, just – think about it. Deeply. Then forget it. And an idea will jump up in your face.

Our train of thought springs into existence already in motion and it speeds between ideas connected by tracks in our mind. Though we cannot access the underlying web of knowledge directly, we experience the result of its traversal. And by training and ruminating on new ideas we integrate them into the network. This is why jazz musicians can fling out new melodies every night. A chord change played by the backing band illuminates melodic pathways carved into the musician’s mind during training. At the gig they just get behind their instrument and go for a ride.

We tap into these networks not only for spontaneous improvisation but also for careful design. We draw from a well of memories and impressions, questions and conclusions, recreating and appropriating them for new purposes. A musician composes from real feelings, from their desires and their fears. A fiction writer sketches a character from the outlines of real people, from the beauties they’ve admired and faults they’ve despised.

This personal reservoir is where filmmaker David Lynch fishes for the strange and abstract ideas that appear in his work. In his book Catching the Big Fish: Meditation, Consciousness, and Creativity, Lynch describes his process more as catching ideas than creating them. He receives ideas from something inside himself, and consults this inner source to develop and implement them.

Lynch isn’t the only prolific artist with a mysterious inner partner. Novelist Cormac McCarthy is well aware of his own collaborator. He said:

Writing can be like taking dictation.

Like Poincaré and Pilkington, McCarthy has talked about the mysterious experience of receiving answers from the ether:

I’d been thinking about [the problem] off and on for a couple of years without making much progress. Then one morning…as I was emptying [the wastebasket] into the kitchen trash I suddenly knew the answer. Or I knew that I knew the answer. It took me a minute or so to put it together.

McCarthy often talks about the Night Shift, the period when we sleep and the invisible thinker takes over. Pilkington agrees – from his book The Moaning of Life:

I think I’m more intelligent in my dreams than I am when I’m awake… A few months ago I went to bed with a problem, fell asleep thinking about it and when I woke up I had a solution.

The invisible thinker rules this hidden world where our creativity lives. It collaborates with us to devise and improvise, and it even thinks for itself. When relieved from its duty as our advisor, it roams freely, eager to satisfy its own curiosity. We heighten our creative potential when we deepen understanding with our internal agent. Especially if we don’t just ask but also listen.

Behind your thoughts and feelings, my brother, there stands a mighty ruler, an unknown sage — whose name is self. In your body he dwells; he is your body. There is more reason in your body than in your best wisdom.

Friedrich Nietzsche, Thus Spake Zarathustra (Kauffman translation, 1954, p.146)