Not the person who does not know anything about the higher worlds can determine whether it exists or not, but he who actually has knowledge about it. [….] The spiritual researcher says nobody can decide what another person may or may not know, but each can only decide for him- or herself what he/she knows. […] It is alleged that Anthroposophy leads to spiritual arrogance, because it claims that it has access to knowledge that rises above ordinary knowledge. But just the opposite is true. There is no greater pride than that which would decide not only about what he doesn’t know, but even would decide on what human beings may or may not know. The real pride is actually expressed in that which defines itself as the norm for all people.
Source (German): Rudolf Steiner – GA 56 – Die Erkenntnis der Seele und des Geistes – Berlin, October 10, 1907 (page 18)
Translated by Nesta Carsten-Krüger