The whole of occult science must spring from two thoughts that can take root in every human soul. For the occult scientist, as he is meant here, these two thoughts express facts that can be experienced if we use the right means. For many people these thoughts signify extremely controversial statements about which there may be wide differences of opinion; they may even be “proved” to be impossible.
These two thoughts are the following. First, behind the “visible” there exists an invisible world, concealed at the outset from the senses and the thinking bound up with the senses; and second, it is possible for man, through the development of capacities slumbering within him, to penetrate into this hidden world.
One person maintains that there is no such hidden world, that the world perceived by means of the human senses is the only one, that its riddles can be solved out of itself, and that, although the human being at present is still far from being able to answer all the questions of existence, a time will surely come when sense experience and the science based upon it will be able to give the answers.
Others state that we must not maintain there is no hidden world behind the visible, yet the human powers of cognition are unable to penetrate into it. They have limits that cannot be overstepped. Let those who need “faith” take refuge in a world of that kind: a true science, which is based upon assured facts, cannot concern itself with such a world.
There is a third group that considers it presumptuous if a man, through his cognitive activity, desires to penetrate into a realm about which he is to renounce all “knowledge” and be content with “faith.” The adherents of this opinion consider it wrong for the weak human being to want to penetrate into a world that is supposed to belong to the religious life alone.
It is also maintained that a common knowledge of the facts of the sense world is possible for everyone, but that in respect of supersensible facts it is only a matter of the personal opinion of the individual, and that no one should speak of a generally valid certainty in these matters.
Others maintain still other things.
Source: GA 13 – An Outline of Occult Science – 1. The Character of Occult Science
Translated by Maud and Henry B. Monges and revised for this edition by Lisa D. Monges