Revolution implies suddenness, as with the American and French revolutions which lasted a few years; but the Industrial Revolution was not a sudden event. However, other phenomena have been described as revolutions while occurring over a long period of time. The Scientific Revolution of the sixteenth and seventeenth centuries is a case in point. The fact is that the phrase ‘Industrial Revolution’ is now so ingrained that there is no point in trying to jettison it. What is important is to establish the different ways in which historians have conceptualised the ‘revolutionary’ nature of the changes.
Some have seen ‘revolution’ as shorthand for large-scale structural change in the economy; such a dramatic word is used to highlight the extent of the changes. In this view, the Industrial Revolution was a continuation of earlier change; it was not different in kind but merely in degree. Therefore its causes were not novel but rooted in the past, and the agenda for historical research is to chart the progress and exact nature of the changes. To others, however, the Revolution constituted a complete shift in the process of economic growth: it was this which was revolutionary. According to this interpretation, before the eighteenth century there was no mechanism by which long-term sustainable growth could take place. By the mid-nineteenth century such growth was an established fact of life: for the first time rapid population increase was accompanied by sustained growth in income per person. The revolution lay not in the speed, but in the shift from a hitherto inevitable correlation between increasing population and declining income per person. The most important thing, for these historians, is to discover why the changes occurred, and why they occurred in this particular period.