Rudolf Steiner

 

There slumbers in every human being faculties by means
of which he can acquire for himself a knowledge of higher
worlds.  Mystics, Gnostics, Theosophists - all speak of a
world of soul and spirit which for them is just as real as
the world we see with our physical eyes and touch with our
physical hands.

 

[...] Just as in the body, eye and ear develop as organs of
perception, as senses for bodily processes, so does a man
develop in himself soul and spiritual organs of perception

through which the soul and spiritual worlds are opened to him.