Why do human beings dream of flying? Not in airplanes or helicopters, but on their own—effortlessly, weightlessly, the way we do in sleep?

The question “Why don’t we fly like birds?” sounds like something a child might ask on a summer afternoon, but it turns out to be one of the oldest and most persistent riddles of human existence. It is a question not merely about missing wings or inadequate muscles, but about the strange mismatch between the freedom we imagine and the bodies we inhabit.

In this book, Boris Kriger takes the reader on a sweeping journey through myth, philosophy, evolutionary biology, biomechanics, aerospace psychology, and emerging flight technology to explore what the dream of flight really means. From Plato’s winged soul to Nietzsche’s eagle, from the hollow bones of birds to the wasting muscles of astronauts, from the ancient Sumerian glyph for “ascent” to the modern jetpack, Kriger weaves together science and reflection to reveal that the longing to fly is not a fantasy to be outgrown but the deepest expression of a consciousness that refuses to accept the verdict of gravity.

Part natural history, part philosophical meditation, part speculative adventure, Why We Don’t Fly Like Birds is a book for anyone who has ever looked up at the sky and felt, for just a moment, that they did not entirely belong on the ground.