One should observe not only Ours but also the Black Brotherhood. It is erroneous to minimize the strength of the dark forces. Very often their victory is due to such neglect. People very often say, “They are not worth thinking about.” But one ought to think about everything existing. If people justifiably protect themselves against thieves and murderers, so much the more should they guard against the assassins of the spirit. (FW II (opens in new tab), 13)