Spiritual science attempts to speak about non-sensory things in the same way that the natural sciences speak about sense-perceptible things...No one can ever deny others the right to ignore the supersensible, but there is never any legitimate reason for people to declare themselves authorities, not only on what they themselves are capable of knowing, but also on what they suppose cannot be known by any other human being.

An Outline of Esoteric Science (ed. SteinerBooks, 1997) - ISBN: 9780880108393