By its nature, set theory does not depend on any previous mathematical knowl- edge. Hence, an individual wanting to read this book can best find out if he is ready to do so by trying to read the first ten or twenty pages of Chapter 1. As a textbook, the book can serve for a course at the junior or senior level. If a course covers only some of the chapters, the author hopes that the student will read the rest himself in the next year or two. Set theory has always been a sub- ject which people find pleasant to study at least partly by themselves. Chapters 1-7, or perhaps 1-8, present the core...