There have always been, at least in nucleus, three main Schools of Philosophical practice [...]
It is customary to describe these three Schools as Yellow, Black and White. The first thing necessary is to warn the reader that they must by no means be confounded with racial distinctions of colour; and they correspond still less with conventional symbols such as yellow caps, yellow robes, black magick, white witchcraft, and the like.
These Schools represent three perfectly distinct and contrary theories of the Universe, and, therefore, practices of spiritual science. The magical formula of each is as precise as a theorem of trigonometry. Each assumes as fundamental a certain law of Nature, and the subject is complicated by the fact that each School, in a certain sense, admits the formulæ of the other two. It merely regards them as in some way incomplete, secondary, or illusory.
Now, as will be seen later, the Yellow School stand aloof from the other two by the nature of its postulates. But the Black School and the White are always more or less in active conflict; and it is because just at this moment that conflict is approaching a climax that it is necessary to write this essay. The adepts of the White School consider the present danger to mankind so great that they are prepared to abandon their traditional policy of silence, in order to enlist in their ranks the profane of every nation.
The Yellow School could not remain impassive spectators of the abominations. Madame Blavatsky was a mere forerunner. They, in conjunction with the Secret Chiefs of the White School in Europe, Chiefs who had been compelled to suspend all attempts at exoteric enlightenment by the general moral debility which had overtaken the races from which they drew their adepts, have prepared a guide for mankind. This man, of an extreme moral force and elevation, combined with a profound sense of worldly realities, has stood forth in an attempt to save the White School, to rehabilitate its formula, and to fling back from the bastions of moral freedom the howling savages of pessimism. Unless his appeal is heard, unless there comes a truly virile reaction against the creeping atrophy which is poisoning them, unless they enlist to the last man under his standard, a great decisive battle will have been lost.
This prophet of the White School, chosen by its Masters and his brethren, to save the Theory and Practice, is armed with a sword far mightier than Excalibur. He has been entrusted with a new Magical formula, one which can be accepted by the whole human race. Its adoption will strengthen the Yellow School by giving a more positive value to their Theory; while leaving the postulates of the Black School intact, it will transcend them and raise their Theory and Practice almost to the level of the Yellow. As to the White School, it will remove from them all taint of poison of the Black, and restore vigour to their central formula of spiritual alchemy by giving each man an independent ideal. It will put an end to the moral castration involved in the assumption that each man, whatever his nature, should deny himself to follow out a fantastic and impracticable ideal of goodness. Incidentally, this formula will save Physical Science itself by making negligible the despair of futility, the vital scepticism which has emasculated it in the past. It shows that the joy of existence is not in a goal, for that indeed is clearly unattainable, but in the going itself.
This law is called the Law of Thelema. It is summarised in the four words, "Do what thou wilt."
Aleister Crowley, “Magick Without Tears”