Raja Yoga is defined as the science of spiritual union through right use of the mind. Yoga literally means "yoke", that which binds two factors together to form a united whole. It refers symbolically to the need to achieve union between our lower and higher natures, and embodies a process whereby the separation between the various aspects of the human being—physical body, emotional nature, intellect/concrete mind, and spiritual self—is overcome, resulting in unity. The key factor in this is the mind and its right use.

One of the fundamental necessities of Yoga, as of all true spiritual methods, is a spiritual re-orientation—a process of cultivating the spiritual values. This entails understanding our attachments and material desires, and how these give rise to our hardships, and how attachment is itself based upon avidya, or spiritual unknowing. Patanjali describes avidya as the confusion between the Self and those things which constitute the not-self. For ages we have identified with those things that are outside of the true self, giving rise to false desires, incorrect perception, and harmful thoughts, words and actions. All of these are obstacles to direct knowledge of our true nature, and to its free expression.

"Avidya is the condition of confusing the permanent, pure, blissful and the Self with that which is impermanent, impure, painful and the not-self." — Patanjali

Through study of spiritual philosophy, daily practice of meditation, and continuous practical application of all that is known and inwardly realised, obstacles to Yoga are eliminated and a consciousness-bridge is built between the higher self and the personality. Illumination and a centering of the yogi's consciousness within the Self are the result. Then "the Yogi knows himself as he is in reality," and knows unity with all things. But the study of Yoga is not primarily for self-benefit. Its primary motivation is to become a helper of one's fellow human beings and a server in the world. This is its natural and inevitable unfoldment.