Bearing in mind that Black and White are semantically charged colors, here's a definitive explanation of "Black Magic."
"Black Magic" is any form of occult ritual, practice or belief system which the observer considers unethical or forbidden by the observer's religious or philosophical beliefs.
Therefore the contents of any semantic bag labeled "Black Magic" will differ depending on who's holding the bag.
To a non-occultist imbued perhaps with Christian doctrine, pretty much anything "occult" fits in that bag.
For a follower of the Eckankar system, any practice tapping into the energies of the three lower chakras is "Black Magic" in that it uses powers too corrupted by their fleshly functions to have any spiritual value...as if God had placed these chakras in our psychic bodies for no other purpose than to tempt us.
Theosophy, thanks to an early 20th Century Christian parson who influenced its beliefs, places the Svadhisthana Chakra (lower abdomen in most other systems and generally thought to govern sexual activity) off to one side of the central column on which all the other chakras are aligned. This had the effect of relieving Theosophists of any responsibility for mastering their sexual energy, while at the same time & in the pure blind fashion of unadulterated Puritanism, calling attention to the Svadhisthana ("What's it doing off to the side like that? What's it for?").
In Thelemic Magick, as taught by the Master Therion (Aleister Crowley), use of all the body's energies is not only permitted but required. You don't attain adepthood, saintliness or whatever without processing your total self and then projecting it successfully across the Abyss that separates individual from cosmic consciousness. This works only when the energies of the lower chakras (associated with ego, hunger, sex, physical survival, etc.) have been accepted and integrated with the energies of the higher chakras (intelligence, feeling, astral perception and spiritual enlightenment). That level of magick is sublimely above the subjective "black" and "white" adjectives;
it is a matter between the self and whatever it is that runs the Universe.
So a Thelemic magician's semantic bag labeled "Black Magic" does not contain many of the items contained in other people's similarly labeled bags. But it is not empty. Rituals not consciously or unconsciously consonant with one's True Will (roughly, the reason one is here) end up as a sort of "Black Magick" in that they fail of the intended result but produce another result, meditation upon which may point the magician closer to his True Will.
Then there is the magick of preventing change. The sacrifice of infant humans in order to build up from their undirected energy an astral counterpart of the psyche of the practitioner, ego, id and all. To prolong one's incarnation till the vessel's leaks can no longer be patched in secret clinics. To reincarnate one's entire persona while bypassing spiritual evolution and to reenter this dimension exactly as one left it: priveleged and powerful.
"Change is stability," Crowley wrote. But to the babykilling adepts of the Illuminati or New World Order, their species of Magick is not at all black.
So, to repeat: "Black Magic" is any form of occult ritual, practice or belief system which the observer considers unethical or forbidden by the observer's religious or philosophical beliefs.
This is the only correct definition of the term. It applies to all cases, and places the onus of its use correctly upon the user. I would however encourage continued use of the term "Black Magic" simply because the more it is used, the less useful it will become, and like all useless terms eventually disappear from the language.
Oliverhaddo
Serving Freedom
and Liberty
