Stanislaw Lem has written, in the introduction to Imaginary Magnitude, his collection of introductions to nonexistent books, that it is time to recognise the introduction as an art form independent of the book. Thus the essence of the book can be packed into the introduction, and the writing of such an independent introduction will obviate the need for the book to which it refers. Whether or not the stand-alone introductions that constitute the body of Imaginary Magnitude bear out this claim I do not know; I have read only the introduction to the collection, which convinced me that I might be encumbering my mind with unnecessary and redundant information if I were to read any further. In any case, what you are reading now bears the label "preface", not "introduction", so rest assured that it's okay for you to read the accompanying book.
In December, 1988, I set out to write a short textbook for the introductory computer science course that I teach along with other instructors for the Johns Hopkins University Center for the Advancement of Academically Talented Youth (CTY). At that time this was to be a purely technical work, explicating what is lectured on in class and nothing else. But as I developed the outline for this work I felt increasingly that something wasn't right with it; there was a huge chunk being left out. I felt that if this book were to have meaning I would have to include in it a motivation for all the technical material. I would have to express to my students the delight with expression and meaning that brought me into the field of computer science.
Making those feelings explicit enough to set down on paper has been a great learning experience for me. I hope that this book will convey to the reader more explicitly the harmonies that were only inklings in the back of my mind when I was getting into computer science, the harmonies whose development has lately led me into the study and the creation of literature and will lead me into other domains in the future. The historical research that has gone into the creation of this book has caused me to place my own efforts and my personal philosophical development more in context.
You will find this book unorthodox, as much of it has been written at least as much for the enlightenment of the author as for that of the students. Whether or not it would be useful as a textbook outside of my own course is unknown to me; that depends upon the personality of the instructor and the nature of the students. I hope that it will at least be provocative and enjoyable reading for anyone with an interest in mathematical thinking. The more technical sections are marked in the table of contents. They may be skipped by the casual reader or by the reader who is already familiar with their contents. This book is aimed at CTY students, and CTY students are in many ways an atypical population. The students in CTY Computer Science 1 are from grades seven through ten and are selected for their above-average mathematical and verbal abilities. (The selector is, unfortunately, a standardised test, but given the volume of applicants there is not much that can be done about this.) While they are in general capable of work normally encountered only in college or graduate school, they require a presentation geared to their own background and level of development. This book is intended to fill a gap by combining advanced subject matter with a presentation directed at the younger student. In my course at CTY, I have used the technical discussions as a supplement to the lectures and have left the literary and historical discussions as optional leisure reading.
In CTY Computer Science 1 we use many examples and exercises to demonstrate the technical principles that I have included in this book; the book is not meant to stand alone, without such support. Most of the exercises in this book are taken from Computer Science 1. They have been compiled by all the instructors over the years in which the course has been offered, and I certainly make no claim to originality on them. The exercises that I have included in this book are a representative set; the text does not concentrate on exercises, because plenty of these can be found in other texts, and there is no calling for a reinvention of the wheel here. The focus instead is on the style of presentation. That is the novelty of this work.
M.K.B.
Ithaca, New York
September 1989