In Instructions such as these, which are to be read by the general public it would be most unwise to give more explicit directions. Enough has been left unsaid to make it impossible for any but a deeply learned student to arrive at the necessary correlations which will enable him to carry forward the "work of the interludes", in which alone magical work can be done. You might ask: Why is this so? Why are the secrets of the breath so carefully guarded? Because the efficacy of black magic is found right here. There is a point where both black and white magic employ necessarily one similar stage in the work. [519] Certain men, with potent wills and clear and trained minds, but animated by purely selfish purpose, have learnt to use the lower of the two soul interludes - that which concerns the relation of mind and brain. Through an intense application and a knowledge of the science of the centers they have been enabled to work out their selfish plans and to impose their will and mental authority upon the "prisoners of the planet". Thus they have wrought much harm. They have no desire to participate in the higher interlude wherein the soul is active, and the mind responsive. The intellectual activity and the responsiveness of the brain to mind impression is all that concerns them. Both white and black magicians, as you see, employ the lower interlude, and both know the significance of the physical breathing interludes. But the white magician works from the soul level out into the manifested world and seeks to carry out the divine plan, whilst the black magician works from the level of the intellect as he seeks to achieve his own separate ends. The difference is not only that of motive, but also of alignment and the radius of the consciousness and its field of expansion. Hence you will see why such extreme caution is evidenced by all true teachers, as they endeavor to teach the nature of the magical work. Only the tested and the true, only the unselfish and the pure can be given the full instructions. All can be given the information concerning the major interludes of soul-mind and mind-brain. Only a few can as yet be trusted with the significant information concerning the minor interludes, carried on in the physical body between breaths and in the brain consciousness.