给学生读者的话PREFACE FOR THE STUDENT

PREFACE FOR THE STUDENT

1. Please don't read the Preface for the Teacher. 2. I will ask of you only the ability to read English and to think logically—no high school mathematics, and certainly no advanced mathematics. …… As a matter of fact, there would be difficulty whatever in introducing the so-called positive integers. 3. Please forget what you have learned in school; you haven't learned it. Please keep in mind everywhere the corresponding portions of your school work; you haven't actually forgotten them. 4. The multiplication table is not to be found in this book, not even the theorem 2·2 = 4; but I would recommend, as an exercise in connection with Chapter 1, § 4, that you make the following definitions: 2 = 1 + 1, 4= (((1 + 1) +1) +1), and then prove the theorem. 5. As is well known, my daughters have been studying (Chemistry) at the University for several semesters already and think that they have learned the differential and integral calculus in College; and yet they still don't know why

x·y = y·x. Berlin, December 28, 1929. Edmund Landau