Now, however, weface an Age of Discontinuity in world economy and tech- nology. We might succeed in making it an age of great economic growth as weil. But the one thing that is certain so far is that it will be a period of change-in technology and in economic policy, in industry structures and in economic theo- ry, in the knowledge needed to govern and manage, and in economic issues. While we have been busy finishing the great nineteenth-century economic ed- ijice, the foundations have shifted beneath our feet. Peter F. Drucker, 1968 The A~e Qf DiscQntinuity, p. 10 This project has had a lQng gestatiQn period, probably ultimately dating to a YQuthful QbsessiQn with watershed divides and bQundaries. My awareness Qf the problem Qf discQntinuity in eCQnQmics dates tQ my first enCQunter with the capi- tal theQry paradQxes in the late 1960s, the fruits Qf which can be seen in Chapter 8 Qf this book. This awareness led tQ a frostratiQn Qver the apparent lack Qf a mathematics Qf discQntinuity, a lack that was in the process of rapidly being QverCQme at that time.