This is a question that often arises when talking about the act of hypnosis.
We read for example in one journal - THEOSOPHY, Vol. 26, No. 10, August, 1938 (Pages 434-440):
In Hypnotism the operator paralyzes that channel in the brain through which the subject, as Ego, operates and controls that organ. This action prevents the subject from receiving any other impressions than those suggested by the operator. This practice has always been named Black Magic by the true adepts because it is an interference with the free-will of the Ego. Any person, therefore, who practices hypnotism is well on the road to becoming a Black Magician. Hypnotism acts upon the capillary veins and nerves from without, as a repression. But in Mesmerism the case is reversed. Here the effect is produced from within without — an opening up instead of a repression and contraction. In Mesmerism the operator does not interfere with the free-will of his patient, and the subject continues to move in accordance with his own nature and qualities.
What do I think?
I think if a person is seriously ill, it doesn’t interest them whether the magic which helps is black or white, just that it helps. When the person agrees that the hypnotist is allowed to impose his will, then it is okay. I had always concerns about using hypnotism because of this reason, but in the end it is the same if you use your hands on the body of a person or if you direct your thoughts towards a person or use clairvoyance. What helped me to overcome this, is the thought that the other one is only an outer appearance of myself coming to me and then we can do what might help. On the subconscious level we are one and from there working seems to be best…