It is true, not everyone today can cross the threshold to the spiritual world; but no one would be prevented from perceiving the truth of what is said by those who have crossed that threshold. It is false reasoning when it is said again and again by one or another: How am I to know that what is presented by anyone as the science of initiation is correct, when I cannot myself see into the spiritual world? That is false reasoning. Common sense which is not led astray by the erroneous ideas of our time in the natural or the social sphere can decide of itself whether the element of truth rules in what anyone says. If someone speaks of spiritual worlds, you must take account of everything: the manner of speaking, the seriousness with which things are treated, the logic which is developed, and so on, and then it will be possible to judge whether what is presented as information about the spiritual world is charlatanism, or whether it has foundation. Anyone can decide this.
Source: Rudolf Steiner – GA 194 – The Mysteries of Light, of Space, and of the Earth – Lecture III: Historical Occurrences of the Last Century – Dornach, 14th December 1919
Translated by Lisa D. Monges