ι De Somniis α Causa per Accidens from the Book of Wisdom or Folly in The Libri of Aleister Crowley

Secundo, the psychic condition of the Sleeper, the Dream being determined by recent Events in his Life, usually those of the Day previous, and especially such Events as have caused Excitement of Anxiety, the more so if they be unfinished or unfulfilled. But this exciting Cause is of a superficial Nature, as it were a Cloke or a Mask; and thus it but lendeth Aspect to the other Cause, which lieth in the Nature of the Sleeper himself.” [via]