We have now reached a stage in human development where the study of spiritual matters must be based on the same foundations as the study of nature was three or four centuries ago.Spiritual science intends to achieve similar things for knowledge of the spirit as Copernicus, Galileo and Giordano Bruno did for the understanding of physical nature in their own time. Of course, the systematic exploration of the spirit in our age encounters the same kind of resistance and hostility as the study and the concepts of the natural sciences did then. Spiritual science will be assimilated into our culture as slowly and with just as much difficulty as the natural sciences were.
We will investigate the spirit with processes of the human mind that are still unknown today, or at least unpopular with most people. Clairvoyant research, as we can call these processes, provides the foundation for spiritual science, and I am speaking to you today on that basis.
Clairvoyant research is discredited by the countless prejudices people have against it, and also by the widespread misuse of the term “clairvoyant investigation.” That is why I want to say right now that I am not speaking from the standpoint of the occult knowledge so often promoted by charlatans these days, but based on the kind of clairvoyant, esoteric knowledge that can be supported even by people firmly grounded in serious research in the natural sciences who base their knowledge on genuine scientific facts. In terms of its inner logic, its mode of thinking, spiritual science belongs to the stream of modern thinking that includes the natural sciences. The two differ only in the areas they research. The natural sciences examine the world of nature, the physical phenomena around us, while spiritual science studies an area that must necessarily remain hidden to the natural sciences, namely, spiritual experience, and spiritual beings.
Source: Rudolf Steiner – GA 154 – The Presence of the Dead on the Spiritual Path: LECTURE FIVE – THE BLESSING OF THE DEAD – Paris, May 26, 1914
Translated by C. von Arnim