The creation of this book and the science it describes has been a vast personal undertaking, spanning the better part of half my life so far. And for it to all have been even remotely possible has required a series of particular personal circumstances. Foremost among them is that I have lived at the moment in history when technology has first made it possible to do the kinds of things I have done. But also crucial has been that my early successes in science and business have for more than twenty years allowed me to be free to pursue the personal intellectual objectives I have chosen.

That by my late teenage years I had already become established in science was what originally provided the personal confidence and practical situation that made it possible for me to embark on an intellectual project as ambitious as this. My early experiences—particularly in physics and computing—were crucial in pointing me in the basic direction I took. My work in designing and documenting Mathematica and its forerunners was central in developing for me a certain definite pattern of clear thinking. My experiences in business were also important in helping me form a capacity for making strategic intellectual decisions. And the fact that for most of my life I have tried to learn as broadly and deeply as possible about science and other fields has provided me a crucial base of knowledge. But more than anything else what has finally allowed me to create the new kind of science in this book is Mathematica. For while building Mathematica has taken a considerable amount of my time, I would without it as a tool never have been able to do the vast majority of what is now in this book.

In my early years I was very much a part of the traditional scientific community. But had I remained there I have little doubt that I would never have been able to create something of the magnitude that I describe in this book. For even just to spend so many years on a single project outside of existing disciplines—and without publishing anything about it—would likely have become impossible even in the highly favorable academic circumstances in which I found myself.

But with the commercial success of Mathematica and Wolfram Research there have for many years not been any such issues for me. And indeed, within my company I have been able to build up a remarkable group of people—who have supported my efforts in all sorts of ways. Over the past fifteen years hundreds of members of our R&D and engineering groups have worked to take my ideas for Mathematica and turn them into finished software that I and millions of others rely on every day. And at one time or another almost every major department of my company has provided help that has been crucial to some aspect of the creation or production of this book.

Yet what is probably most striking is that even in my role as CEO of a highly active company I have for more than ten years been able to devote the large amounts of time that have been required to write this book and develop the science it describes. And more than anything else, what has made this possible is the outstanding team that has helped manage the ongoing operations of the company—especially our current executive committee: George Beck, Roger Germundsson, Theodore Gray, Becky Porth, Brenda Skelly, Tom Wickham-Jones and my brother Conrad Wolfram.

To pursue a project of the length and intensity of this book would not have been possible without the great personal support of my family and friends. Particularly crucial have been my wife—who has contributed both directly and indirectly to many aspects of the form and content of this book, and my children—whose excitement about the world has provided continual encouragement and stimulation. Also important—especially in my youth—were my parents, who supported my early interests and direction.

Like almost any highly creative project, the writing of this book has ultimately been a quite solitary and personal matter. But I have been fortunate over the years to employ a variety of talented assistants, who have helped the project in many different ways: Eric Berg (project management, 2000–2001), Jason Cawley (historical and philosophical issues, 2001–2002 and before), Matthew Cook (technical content, particularly constructions and proofs, 1991–1998), Andrew de Laix (technical content and book production systems, 1998–2002), Matthew Frank (mathematical and historical issues, 2001–2002), Andrea Gerlach (fact finding and checking, 1999–2002), David Hillman (constructions and other technical content, 1997–2001), Scott Koranda (book production systems and project management, 1996–1998), Ed Pegg, Jr. (technical content, 2000–2002), Todd Rowland (mathematical issues, 2001–2002), Malgorzata Strzebonska (graphics finishing, 1997–2002), Matthew Szudzik (mathematical issues, 1998–2000, 2001), Øyvind Tafjord (physics and other technical issues, 2001–2002), Kelli Wendt (project management, 2001–2002), Erik Winfree (software development, 1991–1992). Other members of Wolfram Research and Wolfram Media who have made particularly significant contributions include: Larry Adelston (book layout, 2000–2002), George Beck (project management oversight, 2001–2002 and before), John Bonadies (cover design and other issues, 1995, 1991–1999), Cat Boucher (project management, 2001–2002), Jean Buck (library research 1991–1999; many internal and external issues 1999–2002), Jeremy Davis (design, 2000–2002), Deb Forgacs (library research, 2000–2002), Thomasanna Hail (project management assistance, 2001), Yu He (technical issues, 1991–1992), Andy Hunt (font design, 1997–2002), Janice Hunter (book distribution, 2000–2002), André Kuzniarek (book design and production, 1991–2002), Richard Miske (book layout, 2001–2002), Jan Progen (proofreading, 1997–2002), David Reiss (external communications, 2001–2002), Patrick Rice (book build automation, 2001–2002), Brenda Skelly (manufacturing management, 2001–2002 and before), Caroline Small (document quality assurance, 2001), Michael Trott (occasional technical issues, 1994–2002), Allan Wylde (publishing issues, 1998–1999). (See also the colophon at the very end of the book.) My administrative and computer systems assistants have also been crucial in allowing me to maintain the high level of personal productivity needed to pursue and complete this project.

In developing the new kind of science in this book I have benefitted in many ways from the worldwide intellectual community. I have always worked hard to learn as many fields as possible as deeply as I can—and to keep abreast of new developments that emerge. Part of what has allowed me to do this is reading an immense number of books, articles and websites. But over the years what has also been important is that I have interacted personally with a great many individuals, and I have been fortunate that my position in science and technology has brought me into contact at one time or another with the leaders of almost every major technical field.

In the early and mid-1980s I did collaborative work relevant to this book—some published, some unpublished—with several people: Richard Feynman (foundations of physics and computing), Olivier Martin (additive cellular automata), John Milnor (mathematics of