Reinventing medical care could produce hundreds of innovations. Some may be as simple as giving patients greater e-mail and online support from their clinicians, which would enable timelier advice and reduce the need for emergency-room visits. Others might involve smartphone apps for coaching the chronically ill in the management of their disease, new methods for getting advice from specialists, sophisticated systems for tracking outcomes and costs, and instant delivery to medical teams of up-to-date care protocols. Innovations could take a system that requires sixty-three clinicians for a knee replacement and knock the number down by half or more. But most significant will be the changes that finally put people like John Wright and Armin Ernst in charge of making care coherent, coördinated, and affordable. Essentially, we’re moving from a Jeffersonian ideal of small guilds and independent craftsmen to a Hamiltonian recognition of the advantages that size and centralized control can bring.