One who undertakes to represent certain results of scientific spiritual research of the kind recorded in this book, must above all things be prepared to find that this kind of investigation is at the present time almost universally regarded as impossible. For things are related in the following pages about which those who are today esteemed exact thinkers, assert that they will probably remain altogether indeterminable by human intelligence. One who knows and can respect the reasons which prompt many a serious person to assert this impossibility, would fain make the attempt again and again to show what misunderstandings are really at the bottom of the belief that it is not given to human knowledge to penetrate into the superphysical worlds...