If someone asks, “How can I accept in good faith what these researchers say since I am unable to perceive the spiritual world myself?”, then this is completely unfounded. For it is entirely possible merely by reflecting on what is given, to attain the certain conviction that what is communicated is true, and if anyone is unable to form this conviction through reflection, it is not because it is impossible to believe something one cannot see, but solely because his reflection has not been sufficiently thorough, comprehensive and unprejudiced. In order to gain clarity in regard to this point we must realize that human thinking, when it arouses itself with inner energy, is able to comprehend more than is usually presumed. For in thought itself an inner entity is already present that is connected with the supersensible world.
Source: Rudolf Steiner – GA 13 – An Outline of Occult Science–V–Cognition of the higher worlds. Initiation (part 3)
Translated by Maud and Henry B. Monges and revised for this edition by Lisa D. Monges
Previously posted on September 2, 2015