I just started listening to This View of Life by David Sloan Wilson, and I came across a Henry David Thoreau quote that immediately made me think that it named something I have been feeling for some time, but had never quite found the words to express.

“If you have built castles in the air, your work need not be lost. That is where they should be. Now put the foundations under them.”

The quote carried me back nearly forty years to an evening in Italy.

Lynn and I had traveled all day before arriving at a small seaside village after dark. We found a little trattoria overlooking a quiet bay. That night I tasted pesto for the first time—a memory delicious enough to stay with me ever since—but another image has lingered even longer.

Across the water, suspended against the night sky, hung a brilliantly illuminated castle. It seemed impossible. There was no land beneath it, no mountain, no cliff—only darkness. The castle appeared to float in midair like something from a dream.

The next morning the illusion vanished.

In daylight I discovered that the castle rested atop a great rocky promontory that stretched into the sea. The mountain had been there all along. In the darkness I simply couldn’t see it.

As I sat with Wilson’s ideas, that memory returned with unexpected force.

Perhaps this is how we experience civilization itself.

We notice the castles. The great works of art. The cathedrals. The constitutions. The scientific discoveries. The novels that change us. The extraordinary people whose names survive history.

But with time, we begin to notice the mountain beneath them.

The generations of anonymous lives. Teachers and apprentices. Parents and children. Craftsmen and caretakers. Storytellers and neighbors. Countless conversations around countless tables. Every generation receiving something it did not create, shaping it through its own experience, and quietly passing it forward.

Wilson describes culture as a “meaning system.” I find that idea beautiful because it suggests that meaning is not something hidden inside each of us waiting to be discovered. Meaning is something humanity builds together. It is an evolving landscape of thought, memory, imagination, and shared experience.

Recently Molly and I have been exploring GPT as a kind of topography of thought—a landscape where ideas gather into hills and valleys, where concepts find their neighbors and form new pathways. The more I considered Wilson’s words, the more I wondered if culture itself is such a landscape. Every generation reshapes it just a little, leaving behind trails for those who follow while discovering others left by people they will never know.

Perhaps that is what Thoreau meant.

The castles matter. We need dreams worthy of our imagination. But the longer I live, the more I find myself admiring the mountains beneath them—the unseen foundations patiently built by generations who understood that they were not finishing the world.

They were simply helping the next generation find its place to be.