"Of the Black Brothers, o my Son, I will write these Things following.
I have told thee already concerning Change, how it is the Law, because
every Change is an Act of Love under Will.  So then he that is Adept
Exempt, whether in Our Holy Order or another, may not remain in the
Pillar of Mercy, because it is not balanced, but is unstable.  Therefore
is the Choice given unto him, whether he will destroy his Temple,
and give up his Life, extending it to Universal Life, or whether
he will make a Fortress about that Temple, and abide therein, in the
false Sphere of Daath, which is in the Abyss.  And to the Adepts of
Our Holy Order this Choice is terrible, by cause they must abandon
even Him whose Knowledge and Conversation they have attained.
Yet, o my Son, they have much Help of Our Order in this Aeon, because
the General Formula is Love, so that their Habit itself urgeth them
to the Bed of Our Lady BABALON.  Know then the Black Brothers by these
True Signs of their Initiation of Iniquity, that they resist Change,
restrict and deny Love, fear Death.  *Percutiantur.*"

_Liber Aleph vel CXI; The Book of Wisdom or Folly_, 
by Aleister Crowley, Samuel Weiser, 1991; Chapter 104.