The Yogi Philosophy may be divided into several great branches, or
fields. What is known as "Hatha Yoga" deals with the physical body and
its control; its welfare; its health; its preservation; its laws, etc.
What is known as "Raja Yoga" deals with the Mind; its control; its
development; its unfoldment, etc. What is known as "Bhakti Yoga" deals
with the Love of the Absolute--God. What is known as "Gnani Yoga" deals
with the scientific and intellectual knowing of the great questions
regarding Life and what lies back of Life--the Riddle of the Universe.

Each branch of Yoga is but a path leading toward the one
end--unfoldment, development, and growth. He who wishes first to
develop, control and strengthen his physical body so as to render it a
fit instrument of the Higher Self, follows the path of "Hatha Yoga." He
who would develop his will-power and mental faculties, unfolding the
inner senses, and latent powers, follows the path of "Raja Yoga." He
who wishes to develop by "knowing"--by studying the fundamental
principles, and the wonderful truths underlying Life, follows the path
of "Gnani Yoga." And he who wishes to grow into a union with the One
Life by the influence of Love, he follows the path of "Bhakti Yoga."

Yoga is divided into several branches, ranging from that which teaches
the control of the body, to that which teaches the attainment of the
highest spiritual development. In the work we will not go into the
higher phases of the subject, except when the "Science of Breath"
touches upon the same. The "Science of Breath" touches Yoga at many
points, and although chiefly concerned with the development and
control of the physical, has also its psychic side, and even enters
the field of spiritual development.