Michel Foucault once expressed his disagreement with the "breach" between social history and the history of ideas brought about by the assumption that the former is concerned with how people act without thinking, while the latter analyses how people think without acting. "People both think and act," he says, by way of a sarcasm consisting in having to point out the obvious. While in complete agreement with Foucault on this as on several other issues, the author of this book chooses to emphasise another "obviousness" of at least equal importance: that thoughts and (material) actions may well...