What is Yoga?

There are several well-defined systems of Yoga. Each one has its distinct methods and processes. Now what element in these practices mark them out as Yogis? Is it the mere process that can be named Yoga? No. For if it were so, they should yield the fruits of Yoga by whatever way they are practised.

Then concentration, Upasana (worship) of a deity, Japa of particular Mantras, even when done for the purpose of personal gain with some secure or material end in,view would lay claim to the name of Yoga. The expert pearl-diver restrains his breathing under water. Can this then equal the Kumbhak of Pranayama?

These acts cannot lead to Yoga, namely union with the Divine Japa for obtaining issue, Upasana to become wealthy and prosperous, concentration to acquire powers for influencing others, all these are no more Yoga than the occult practices of pseudo-occultists and witch-doctors. Though the methods in themselves may be a limb of the real Yoga, yet a base motive and a destructive or unmoral aim renders them the very antithesis of Yoga. The common under lying element in the various processes that mark them as really Yogic is the lofty motive with which they are inspired, the high ideal they aim at attaining.

Thus, it is that any act going to fulfil the ultimate ideal of Union of the individual soul with the Supreme Spirit becomes Yoga. Else it is not Yoga. This point should be remembered well.

Source: pg. 135, Yoga Samhita by Swami Sivananda