where this book really comes to life is in its descriptions of books--the manuscripts and early editions and incunabula (what a wonderful word!) and fakes and the tracking down of old titles and their provenance. which only makes sense. the goldstones are bibliomanes and at their best writing about other bibliomanics. their thumbnail of what the book business was like in the 17th century is pretty indicative too of modern rare book selling. I've read two of their previous books--used & rare and slightly chipped--both of which were focused on the oddities of bookcollecting and those were wonderful. they try something a little different here--tracing a single author, the spanish author michael servetus, from his influences to the influences he had on others and the fate of his books, which were supposed to be destroyed but as we discover thrillingly nearly at the end of the book, "[john] calvin [who had ordered the burning at the stake of servetus along with all his manuscripts and copies of his books] after ordering every copy...hunted down and destroyed, after threatening anyone who harbored a copy with the same fate as that of its author, could not bring himself to destroy his own copy [of servetus' most heretical work]." this is a satisfying coda to an author's life and death.
but the book doesn't entirely satisfy. the goldstones are on solid ground when, say, tracking down provenance (their section "the trail" detailing the assumed trajectory surviving copies of servetus' last work took in order to end up in various national and private libraries), but less so when trying to explain philosophic concepts or theological arguments. and their views of calvin and the holy roman emperors, all of which are the villains to servetus' scholarly hero, are tellingly simplistic: they operate primarily out of a basis for attaining and holding onto power, as if their beliefs and theologies are beholden to that and not the other way around. the reason john calvin remains a potent religious force to this day is because of his genius for combining scripture and human needs in the service to providing the religious discipline most people acknowledge they need. he remains influential because his strict dogma answers a god-sized hole in people, not despite it.
aside from this and a few other caveats--among them one that has nothing to do with the goldstones but my kindle version of the book often substitutes symbols for numbers when it's obvious there's meant to be a date noted (so it looks like the authors are cursing someone) and sometimes nonsensical numbers appear (for instance, in describing the devastation of the 30 years war, this appears: "no statistic is more chilling than this: there were 11 million people living in germany in 1618...;by 1648...only 13 million were left." what?)--the book is serviceable in delineating a seldom-known precursor to unitarianism as well as providing a sketchbook explanation of what unitarianism is and its expansion from the council of nicea to 19th century america.