Book excerpt: Walking upright on two feet is a uniquely human skill. It defines us as a species. It enabled us to walk out of Africa and to spread as far as Alaska and Australia. It freed our hands and freed our minds. We put one foot in front of the other without thinking - yet how many of us know how we do that, or appreciate the advantages it gives us? In this hymn to walking, neuroscientist Shane O'Mara invites us to marvel at the benefits it confers on our bodies and minds. In Praise of Walking celebrates this miraculous ability. Incredibly, it is a skill that has its evolutionary origins millions of years ago, under the sea. And the latest research is only now revealing how the brain and nervous system performs the mechanical magic of balancing, navigating a crowded city, or running our inner GPS system. Walking is good for our muscles and posture; it helps to protect and repair organs, and can slow or turn back the ageing of our brains. With our minds in motion we think more creatively, our mood improves and stress levels fall. Walking together to achieve a shared purpose is also a social glue that has contributed to our survival as a species. As our lives become increasingly sedentary, we risk all this. We must start walking again, whether it's up a mountain, down to the park, or simply to school and work. We, and our societies, will be better for it.