What can we really know about the world around us? Or is there beauty in daring not to know? With clarity and lightness, acclaimed physicist Carlo Rovelli takes us on a journey of enlightenment, to the speculative frontiers of modern physics and the boundaries of thought. There is no fear in testing their limits, he suggests - not least because there may be no final ground to reach. Here Rovelli shows us that electrons and minds, stones and laws, judgements and galaxies are not essentially different in nature from one another, but rather ideas that illuminate each other. Reality, he reveals, is shaped by a continuous play of reflections. From this emerges his visionary insight- the equality of all things. Like the ancient Chinese philosopher Zhuangzi, who dreams he is a butterfly and wakes unsure whether he is Zhuangzi dreaming to be a butterfly or a butterfly dreaming to be Zhuangzi, Rovelli invites us to see reality anew, recognizing that our knowledge is coherent but also uncertain and circular. We are made of the same stuff as the rest of reality - and so we are, in a deep sense, home in the world.