Blavatsky
Original sense
Occultism is the disciplined study of hidden laws of nature, requiring a purified life. It is, in her contrast, the opposite of spiritualism (passive mediumship) and of ceremonial magic pursued for power. ‘True occultism’ is altruism plus knowledge; without the first, the second is black magic.
Occultism is not magic, though magic is one of its tools. Occultism is the science of the secrets of nature… and it is a science that only the ethically fit may handle.
She tried to rescue ‘occult’ from both churchly denunciation and salon entertainment. The essay above is her clearest warning that psychic tricks without ethics are a fall.