There are a large number of definitions for magic/magick/magik.
I define it as the means
and the process of altering reality to suit
the Will.
Aleister Crowley defined it, in Magic in Theory and Practice as "the Science and Art of
causing Change to occur in conformity with Will." Dion Fortune
defines it thusly: "Magic is the art of changing consciousness at
will." (A quotation by William Butler in Apprenticed to Magic (1962) on p. 12 is the only original source I've traced for this.)
Nevill Drury refered to it as "...the technique of harnessing the secret powers
of Nature and seeking to influence events for one's own purpose."
Isaac Bonewits, who favors not spelling it with a k, defines it
as:
(1) A general term for arts, sciences, philosophies
and technologies concerned with (a) understanding and using various
altered states of consciousness within which it is possible to
have access to and control over one’s psychic talents, and
(b) the uses and abuses of those psychic talents to change interior
and/or exterior realities. (2) A science and an art comprising
a system of concepts and methods for the build-up of human emotions,
altering the electrochemical balance of the metabolism, using
associational techniques and devices to concentrate and focus
this emotional energy, thus modulating the energies broadcast
by the human body, usually to affect other energy patterns whether
animate or inanimate, but occasionally to affect the personal
energy pattern. (3) A collection of rule-of-thumb techniques
designed to get one’s psychic talents to do more or less
what one wants, more often than not, one hopes. It should be
obvious that these are thaumaturgical definitions.
From Isaac Bonewits' website at http://www.neopagan.net/Pagan_Glossary.html
These are some of the clearer definitions that have been given; it is
not hard to turn up many more, some of them extremely
obtuse. In most
modern usage, it is used to refer to their processes of reality
alteration, not to be confused with
stage magic. While some disagree
with this, it is occasionally helpful to have the two spellings,
particularly when one considers situations such as
alt.magic versus
alt.magick. It is notable that some of these definitions would
encompass more "
mundane"
science and
engineering.
Ok, how do you think it could possibly work?
Well, everyone disagrees. Some believe that it just changes the
practicioner mentally in order to produce the desired results. Others
feel it alters the energy one emits, therefore causing an alteration in the environment.
Still others feel it works by getting in touch with supernatural
entities and getting them to do things for you.
Magick seems to follow a set of laws regardless of culture. Whether these
laws say more about the truth of magic or the human mind is open for debate. It can run from
affirmations and folk magick to ceremonial magick, with ritual and such.
Guide to Spellcasting, by
swankivy, gives a fairly good overview of the topic, biased towards a Wiccan ritual-based
view.
Why with a k?
Aleister Crowley is believed the be the main
source of the use of spelling magick with a "k" to distinguish it from
stage magic/legerdemain.
There are a few reasons, none of which can be
proven to the satisfaction of all, as to why Crowley spelled it with a 'k'. First off, "magick"
was the spelling in Elizabethan times, and was used in John Dee's
diaries. This later fell into disuse in favor of the modern spelling by 1800 in
England and by 1840 in the United States.
Given that Crowley considered himself the reincarnation of Edward Kelly, this is one definite
possibility. Another possibility is that since "K" is the eleventh
letter of a few alphabets, and eleven is associated with the Qliphoth,
which are the "underworld forces" that must be overcome in
order to perform magick. A similar argument points to the ancient
Egyptian khu, literally magic power, and relating to the vagina.
Another claim suggests that based on
Crowley's Magick in Theory and Practice, the spelling was changed to
distinguish it not from stage magic, but rather from common Golden Dawn
magic, which Crowley felt was bovine scatology.
This spelling change is apparently a written-only way of distinguishing the usage, as it should be pronounced in the same way. In fact, Mertseger argues (rather well) in magic that the difference is obvious by context and therefore that the spelling is moot. I have, however, heard people pronounce it mag"icik', basically repeating the sound at the end, as well as seen someone claim the pronounciation should be mage-ick.