It is immaterial whether these exist or not. By doing certain things certain results will follow; students are most earnestly warned against attributing objective reality or philosophic validity to any of them.
Before entering upon any of these practices, the student should be in good health, and have attained a fair mastery of Asana,[1] Pranayama[2] and Dharana.[3]
It is desirable that the student should never attach to any result the importance which it at first seems to possess.
(In another book will it be treated of the Expansion and Contraction of Consciousness; progress by slaying the Chakkrams; progress by slaying the Pairs of Opposites; the methods of Sabhapaty Swami, &c., &c.)
[1] Asana originally meant "sitting down", a sitting position. In the practice of Yoga it denoted the art of sitting still, but later was applied to cultivating the ability to remain in seated meditation for extended periods.
[2] Pranayama is "extension of the breath" or "extension of the life force". "Yama" is also often taken to mean "restrain" or "control" rather than "extend".
[3] Dharana is translated variously as "collection or concentration of the mind (joined with the retention of breath)", or "the act of holding, bearing, wearing, supporting, maintaining, retaining, keeping back (in remembrance), a good memory", or "firmness, steadfastness, certainty".