For more than a century, physicists have hoped that they were closing in on the Holy Grail of modern science - a unifying theory that would make sense of the entire physical world, from the subnuclear realm of quarks and gluons, to the very moment of the creation of the universe. This book is a history of the attempts to find a theory of everything, arguing that it will never be found, and warning that the compromises necessary to produce a final theory may well undermine the rules of doing good science. At the heart of the book is the rise of the particle physicists, and their attempts to reach far out into the cosmos for a unifying theory. Working beyond the grasp of the largest telescopes or the most powerful particle accelerators, and unable to subject their findings and theories to experimental scrutiny, they have moved into a world governed by mathematical and highly speculative theorizing, none of which can be empirically verified. David Lindsey argues that a theory of everything derived from particle physics will be full of untested - and untestable - assumptions. And if physicists yield to such speculation, the field will retreat from the high ground of science, becoming instead a modern mythology. This would surely be the end of physics as it is known today.