Quantum theory launched a revolution in physics. But we have yet to understand the revolution's significance for philosophy. Richard Healey opens a path to such understanding. Most studies of the conceptual foundations of quantum theory first try to interpret the theory - to say how the world could possibly be the way the theory says it is. But, though fundamental, quantum theory is enormously successful without describing the world in its own terms. When properly applied, models of quantum theory offer good advice on the significance and credibility of claims about the world expressed in...