It is the best way of understanding how the human world changes, as well as the natural world. Change in human institutions, artefacts and habits is incremental, inexorable and inevitable. It follows a narrative, going from one stage to the next; it creeps rather than jumps; it has its own spontaneous momentum, rather than being driven from outside; it has no goal or end in mind; and it largely happens by trial and error – a version of natural selection.
