This book (Theosophy) cannot be read in the customary manner of the present day. In certain respects every page, and even many sentences, will have to be worked out by the reader. This has been aimed at intentionally because only in this way can the book become to the reader what it ought to be. The one who merely reads it through will not have read it at all. Its truths must be experienced, lived. Only in this sense has spiritual science any value.
The book cannot be judged from the standpoint of science if the point of view adopted in forming such a judgment is not gained from the book itself. If the critic will adopt this point of view, he will certainly see that the presentation of the facts given in this book will in no way conflict with truly scientific methods. The author is satisfied that he has taken care not to come into conflict with his own scientific scrupulousness even by a single word.
Source: Rudolf Steiner – GA 9 – Theosophy – An Introduction to the Supersensible Knowledge of the World and the Destination of Man: From the prefaces to the first, second and third editions
Translated by Henry B. Monges and revised for this edition by Gilbert Church, Ph.D