For the spiritual and the sensual desires are put to sleep and mortified, so that they can experience nothing, either Divine or human; the affections of the soul are oppressed and constrained, so that they can neither move nor find support in anything; the imagination is bound and can make no useful reflection; the memory is gone; the understanding is in darkness, unable to understand anything; and hence the will likewise is arid and constrained and all the faculties are void and useless; and in addition to all this a thick and heavy cloud is upon the soul, keeping it in affliction, and, as it were, far away from God.
-St. John of the Cross