A cutting-edge examination of what it means to be human and to have a 'self' in the face of new scientific developments in genetic editing, cloning and neural downloading. After seeing his own cells used to grow clumps of new neurons – essentially mini-brains – Philip Ball begins to examine the concepts of identity and consciousness. Delving into humanity's deep evolutionary past to look at how complex creatures like us emerged from single-celled life, he offers a new perspective on how humans think about ourselves. In an age when we are increasingly encouraged to regard the 'self' as an abstract sequence of genetic information, or as a pattern of neural activity that might be 'downloaded' to a computer, he returns us to the body to flesh and blood and anchors a conception of personhood in this unique and ephemeral mortal coil. How to Build a Human brings us back to ourselves but in doing so, it challenges old preconceptions and values. It asks us to rethink how we exist in the world.