Virtual Reality is the most effective device ever invented for researching what a human being actually is - and how we think and feel. Virtual Reality has long been one of the dominant cliches of science fiction. Now Virtual Reality is a reality: those big headsets that make people look ridiculous, even while they radiate startled delight at whatever it is they're experiencing in there; the place where war veterans overcome PTSD, surgeries are trialled, aircraft and cities are designed. But VR is far more interesting than any single technology, however spectacular. More than thirty years ago, legendary computer scientist, visionary and artist Jaron Lanier pioneered its invention. Here, in what is likely to be one of the most unusual books you ever read, he blends scientific investigation, philosophical thought-experiment and his memoir of a life lived at the epicentre of digital innovation to explain what VR really is: the science of comprehensive illusion; the extension of the intimate magic of earliest childhood into adulthood; a shared, waking state, intentional, communicative, collaborative dream; a hint of what life would be like without any of the limits. As Lanier shows, we are standing on the threshold of an entirely new realm of human creativity, expression, communication and experience. While we can use VR to test our relationship with reality, it will test us in return, for how we choose to use it will reveal who we truly are. Welcome to a mind-expanding, life-enhancing, world-changing adventure.