"There is only one thing incompatible with work and that is 'professional occultism,' in other words, professional charlatanism. All these spiritualists, healers, clairvoyants, and so on, or even people closely connected with them, are none of them any good to us. And you must always remember this and take care not to tell them much because everything they learn from you they might use for their own purposes, that is, to make fools of other people.