What is found in Knowledge of the Higher Worlds and Its Attainment is apart from other books of instruction in that it is harmless. Only those guide lines are disclosed that cannot do damage to a person, even if they are not followed with patience and perseverance. They can do no harm even if a person practices them improperly.
Source: Rudolf Steiner – GA 53 – The Inner Development of Man – Berlin, December 15, 1904
Translated by Maria St. Goar