The line has in itself neither matter nor substance and may rather be called an imaginary idea than a real object. Leonardo da Vinci wrote this brief statement in one of his notebooks. It provided the impetus for writing this book, along with another observation from the artist Rico LeBrun:

True lines do not exist in nature; we invent them. They are poetic fiction.

Of all the tools in an artist’s toolbox, the line is the most elementary. It is also the most contrived because lines, as LeBrun noted, do not exist in nature. We use lines in drawing to define shapes, but in fact there are no outlines at the edges of objects. I began to notice how often we use lines to represent an idea. I had a growing feeling there was something profound about a line as an imaginary idea. This, I felt, had a much broader significance far beyond its use in art.

“You’ve got a continuity of three million years of very little change. And then, from forty thousand years ago to now—change, change, change—that’s the nature of the game.” That’s anthropologist Harold Dibble from a conversation captured in the book Café Neandertal. Author Beebe Bahrami summarizes the conversation: “Everyone agrees on the rate of change but not on why…. But the fact holds that 40,000 years ago we began doing things differently from all our ancestors of the past three million years, and that only accelerated into a mind-boggling alteration of the world as never seen before.”

Mark of Distinction presents a plausible theory for what catalyst launched our human ancestors onto the path that brought us to the world we live in now. It brings together ideas from paleoanthropologists, neuroscientists, linguists, historians, and artists to consider the possible spark that ignited the human imagination—how a simple prehistoric invention could lead to what has been called the Big Bang of Human Consciousness or the Dawn of Human Culture—and propelled us into the modern world.