When we were at university together, James Philips and I rehearsed for the play Rosencrantz and Guildenstern Are Dead, Tom Stoppard’s play-behind-the-play. Philips played Rosencrantz, who says, upon discovering that Hamlet has given the feckless couple the slip, “Be happy—if you’re not even happy, what’s so good about surviving?” In his first book, Philips has set out to explain the great constitutional project undertaken by the North American colonists of Britain to secure the happy future that his character demanded. In doing so he has brought to bear a lawyer’s concern to discover those foundational aspects of the earlier British…