One can well sense the feeling which this comparison may evoke in many people. One can even understand that he who doubts and holds the above comparison against this labor of thought, does not even faintly sense the whole seriousness of that mental effort. And yet the present writer is not only fully convinced of that seriousness, but is of opinion that that work of thought may be numbered among the noblest achievements of humanity. To show that the human power of vision cannot perceive the cellular structure without the help of instruments, would surely be a useless undertaking; but in exact thinking, to become conscious of the nature of that thought is a necessary work of the mind. It is only natural that one who devotes himself to such work, should not notice that reality may refute him. The preface to this book can be no place for entering into many “refutations” of former editions, put forth by those who are entirely devoid of appreciation of that for which it strives, or who direct their unfounded attacks against the personality of the author; but it must, none the less, be emphasized that belittling of serious scientific thought in this book can only be imputed to the author by one who wishes to shut himself off from the _spirit_ of what is expressed in it. Man’s power of cognition may be augmented and made more powerful, just as the eye’s power of vision may be augmented. Only the means for strengthening the capacity of cognition are entirely of a spiritual nature; they are inner processes, belonging purely to the soul. They consist of what is described in this book as meditation and concentration (contemplation). Ordinary soul-life is bound up with the bodily instrument; the strengthened soul-life liberates itself from it. There are schools of thought at the present time to which this assertion must appear quite senseless, to which it must seem based only upon self-delusion. Those who think in this way will find it easy, from their point of view, to prove that “all soul-life” is bound up with the nervous system. One who holds the standpoint from which this book has been written, can thoroughly understand such proofs. He understands people who say that only superficiality can assert that there may be some kind of soul-life independent of the body, and who are quite convinced that in such experiences of the soul there exists a connection with the life of the nervous system, which the “dilettantism of occult science” merely fails to detect.