The Setian division between Greater and Lesser Magic has its beginnings in the Church of Satan.
In “The Book of Belial” section of The Satanic Bible Anton LaVey writes:
Magic falls into two categories, ritual or ceremonial, and non-ritual or manipulative. Ritual magic consists of the performance of a formal ceremony, taking place, at least in part, within the confines of an area set aside for such purposes and at a specific time. Its main function is to isolate the otherwise dissipated adrenal and other emotionally induced energy, and convert it into a dynamically transmittable force. It is purely an emotional, rather than intellectual, act. Any and all intellectual activity must take place before the ceremony, not during it. This type of magic is sometimes known as “GREATER MAGIC”.
Non-ritual or manipulative magic, sometimes called “LESSER MAGIC”, consists of the wile and guile obtained through various devices and contrived situations, which when utilized, can create “change, in accordance with one’s will”. In olden times this would be called “fascination”, “glamour”, or the “evil eye”.
These simple definitions would become incorporated into Setian practice in a different fashion.
Unlike the Church of Satan, which felt all magic was magic and that any distinction was simply being done to make people feel better, the Temple of Set held a much more refined understanding of the real, rather then simply cultural, difference between White and Black Magic. Dr. Aquino wrote the following in his commentary on The Book of Coming Forth by Night (see Temple of Set by Dr. Michael A. Aquino):
Ritual magic falls into two general categories, White and Black.
These may be distinguished as follows:
White magic is a highly-concentrated form of conventional religious
ritual. The practitioner seeks a focus of his awareness and powers of
concentration via an extreme degree of autohypnosis. The technique
may be used simply for meditation or entertainment through mental
imagery (‘astral projection”). Or it may be used to focus the Will
towards a desired end - a cure, curse, etc. To accomplish this, the
magician envisions a god or daemon with the power to achieve the
goal, then concentrates his Will into an appeal. The god or daemon
then carries out the appeal, more of less effectively - depending
upon the strength of the magician’s conviction of its power as a
Black Magic involved no autohypnosis or conditioning of the mind to
make it receptive to induced imagery. Rather it is a deliberate and
conscious effort to force the mind outward - to impact upon and alter
the”laws” of the objective universe.”
In ”Black Magic" Dr. Aquino writes on Lesser Black Magic:
Lesser Black Magic (LBM) is the influencing of beings, processes, or objects in the objective universe by the application of obscure physical or behavioral laws.
LBM is an impelling (encouraging, convincing, increasing of probability) measure, not a compelling (forcing, making inevitable) one. The object if to make something happen without expending the time and energy to make it happen through direct cause-and-effect.
and on Greater Black Magic:
Greater Black Magic (GBM) is the causing of change to occur in the subjective universe in accordance with the will. This change is the subjective universe may cause a similar and proportionate change in the objective universe.
Later two divisions between the kinds of GBM that exist is made:
You undertake a GBM working because you want to understand something or because you want to change something. The former type may be referred to as an illustrative working, while the latter is often called anoperative working. Each takes effect by expanding and/or altering your subjective universe, which then exerts a corresponding and proportionate influence upon the objective universe - and other subjective universes - via the Magical Link phenomenon.
In addition a third class of Black Magic, Medial Black Magic, is discussed as follows:
It is easy to focus strongly and exclusively on either one or the other of these two categories, so much so that we miss that grey area wherein they blend. Let us call this Medial Black Magic (MBM).
MBM involved the use of the Magical Link in its simplest, most direct form in an operative context. Unlike LBM, in which the magician uses forces and features which are of the objective universe to accomplish his goal, MBM has similar goals but uses metaphysical means - the Magical Link - to realize them. It is not as “pure” as true GBM.
From within this set of definitions the older Church of Satan “magic is magic” attitude becomes clear. What they were engaged in and what those magicians they thought were hypocrites were doing was in fact the same thing: White Magic. The Satanist was simply more honesty about the autohyponsis involved.
Later holders of a similar “magic is magic” attitude, such as those involved in the Chaos Magic movement, would ultimately see the same thing, referring to what they were engaged in as “Sleight of Mind” or more comically “Pulling the Wool over your own eyes.” Peter J. Carroll had the self-awareness to term himself an “Off-White Magician” in his Psybermagick.
White Magic works. It is simply easy to become bogged down by it and to lose your capacity to turn off that auto-hypnosis. With out that capacity you can easily become trapped by the delusions you generate by thinking them real. See the history of religion and religious warfare for a look at the results of those who lose sight of their White Magical Workings and their followers who were unaware of the hypnotic nature of what they are engaged.