Section IV of the Yoga-Sutras provides the theoretical background for the tech-
nique of Yoga which has been dealt with in the previous three Sections. It deals with
the various general problems which form an integral part of the Yogic philosophy and
which must be clearly understood if the practice of Yoga is to be placed on a rational
basis. The practice of Yoga is not a sort of floundering in the Unknown for attaining a
vague spiritual ideal. Yoga is a Science based upon a perfect adaptation of well-
defined means to an unknown but definite End. It takes into account all the factors
which are involved in the attainment of its objective and provides a perfectly coherent
philosophical background for the practices which are its more essential part. It is true
that the doctrines which constitute this theoretical background will hardly appear ra-
tional or intelligible to people who are not familiar with this subject but that is true of
any kind of knowledge which deals with problems of an unfamiliar nature. It is only
those who have given considerable thought to this subject and are familiar at least with
the elementary doctrines of the Yogic philosophy who can be expected to appreciate
the grand and almost flawless line of reasoning which underlies the apparently discon-
nected topics dealt with in Section IV.
As this Section deals with many difficult topics which are apparently uncon-
nected, it will perhaps help the student to grasp the underlying thread of reasoning
running throughout the Section if a synopsis of the whole Section is given at the be-
ginning. This will inevitably involve some repetition of ideas but such a bird's-eye
view will be definitely helpful in understanding this rather abstruse aspect of Yogic
philosophy.
SYNOPSISSutra 1: This enumerates the different methods of acquiring Siddhis. Of the five
methods given only the last based upon Samadhi is used by advanced Yogis in their
work because it is based upon direct knowledge of the higher laws of Nature and is,
therefore, under complete control of the will. The student must have noticed that all
the Siddhis described in the previous Section are the result of performing Samyama.
They are the product of evolutionary growth and thus give mastery over the whole
range of natural phenomena.