We live in a time of great uncertainty about the future. Those heady days of the late 20th century, when the end of the Cold War seemed to be ushering in a new and more optimistic age, now seem like a distant memory. During the last couple of decades we've been battered by one crisis after another and the idea that humanity might be on a progressive path to a better future seems like a grand illusion. And yet it is only now, as disillusioned...