For this edition I have almost entirely rewritten the opening chapter
on the character of Occult Science. I think there will now be less
cause for misunderstanding. How often have I heard it said: While
other branches of learning offer scientific proofs, this pretended
science merely declares that such and such are the findings of Occult
Science. It is a natural objection. The proof of supersensible
knowledge can never be as tangible and compelling as with things seen
and experienced by the outer senses. It is a misconception none the
less, and in the altered version I have tried to bring this out more
clearly than I appear to have succeeded in doing in the earlier
editions.
For the rest, I have introduced changes and additions, trying to make
the explanations clearer and more cogent. In many parts of the book,
the oft-repeated experience of the spiritual realities described
convinced me of the need to modify the forms of expression in which I
try to clothe them, and I have done my best to make the necessary
changes.