The necessary precondition for all the exercises
We can however understand from this how necessary it is that man should not demand entry into the spiritual world until he has learned and understood certain essential truths of that world by the simple exercise of his everyday intelligence, developed in the physical world. If spiritual development follows the right and normal path, then before he aspires to enter the supersensible world the pupil will already have mastered with his ordinary intelligence the whole of the earlier contents of this book.
Chapter V of Occult Science: an Outline (`Knowledge of Higher Worlds. Concerning Initiation’)