What is your favourite model of biological evolution? Whether it is rungs on a ladder, the ever-branching tree, or even the more modern image of movement between peaks in a 'fitness landscape', chances are it treats time in just one way: later means better...The idea of evolution was the child of the hopes of progress, as Michael Ruse puts it in Monad to Man, his impressive 'philosophical history' of these notions...Ruse tracks down [this] tendency in the work of innumerable writers...All this makes [his] book a superb summary of the views of every major evolutionist. The result is unfailingly interesting. Ruse presents much to argue with, both for aficionados of evolution and for theorists of science.