Raja Yoga ("royal yoga", "royal union", also known as Classical Yoga or simply Yoga) is one of the six orthodox (astika) schools of Hindu philosophy, outlined by Patanjali in his Yoga Sutras. Raja yoga is concerned principally with the cultivation of the mind using meditation (dhyana) to further one's acquaintance with reality and finally achieve liberation.

The term Raja Yoga is a retronym, introduced in the 15th century Hatha Yoga Pradipika to distinguish the school based on the Yoga Sutras from the new current of Hatha Yoga. The term was later used to describe the entirely unrelated meditation practice of the Brahma Kumaris involving the focus of one's mind and surrender to a channelled entity they believe to be the Supreme Soul.

Raja Yoga is sometimes referred to as Ashtanga (eight-limbed) yoga because there are eight aspects to the path to which one must attend. This is not to be confused with the Ashtanga Vinyasa Yoga of K. Pattabhi Jois.

Raja Yoga is so-called because it is primarily concerned with the mind. The mind is traditionally conceived as the "king" of the psycho-physical structure which does its bidding (whether or not one has realized this). Because of the relationship between the mind and the body, the body must be first "tamed" through self-discipline and purified by various means. A good level of overall health and psychological integration must be attained before the deeper aspects of yoga can be pursued. Humans have all sorts of addictions and obsessions and these preclude the attainment of tranquil abiding (meditation). Through restraint (yama) such as celibacy, abstaining from drugs and alcohol and careful attention to one's actions of body, speech and mind, the human being becomes fit to practise meditation. This yoke that one puts upon oneself (discipline) is another meaning of the word yoga.

Every thought, feeling, perception, or memory you may have causes a modification, or ripple, in the mind. It distorts and colors the mental mirror. If you can restrain the mind from forming into modifications, there will be no distortion, and you will experience your true Self. - Swami Satchidananda

Patañjali's Yoga Sutras begin with the statement yogas citta-vatti-nirodha, "Yoga limits the oscillations of the mind". They go on to detail the ways in which mind can create false ideations and advocate meditation on real objects, which process, it is said, will lead to a spontaneous state of quiet mind, the "Nirbija" or "seedless state", in which there is no mental object of focus.

Practices that serve to maintain for the individual the ability to access this state may be considered Raja Yoga practices. Thus Raja Yoga encompasses and differentiates itself from other forms of Yoga by encouraging the mind to avoid the sort of absorption in obsessional practice (including other traditional yogic practices) that can create false mental objects.

In this sense Raja Yoga is referred to as the "king among yogas": all yogic practices are seen as potential tools for obtaining the seedless state, itself considered to be the starting point in the quest to cleanse Karma and obtain Moksha or Nirvana. Historically, schools of yoga that label themselves "Raja" offer students a mix of yogic practices and (hopefully or ideally) this philosophical viewpoint.

Raja Yoga aims at controlling all thought-waves or mental modifications. While a Hatha Yogi starts his Sadhana with Asanas (postures) and Pranayama, a Raja Yogi starts his Sadhana with the mind, although a certain minimum of asanas and pranayamas are usually included as a preparation for the meditation and concentration.

Eight limbs of Ashtanga Yoga

The eight limbs of Ashtanga Yoga are:

• Yama - Code of conduct - self-restraint
• Niyama - religious observances - commitments to practice, such as study and devotion
• Asana - integration of mind and body through physical activity
• Pranayama - regulation of breath leading to integration of mind and body
• Pratyahara - abstraction of the senses, withdrawal of the senses of perception from their objects
• Dharana - concentration, one-pointedness of mind
• Dhyana - meditation (quiet activity that leads to samadhi)
• Samadhi - the quiet state of blissful awareness, superconscious state

They are sometimes divided into the lower and the upper four limbs, the lower ones being parallel to the lower limbs of Hatha Yoga, while the upper ones being specific for the Raja yoga. The upper three limbs practiced simultaneously constitute the Samyama.

Yama

Yama consists of five parts: Ahimsa (non-violence), Satya (truthfulness), Asteya (non-stealing), Brahmacharya (celibacy), and Aparigraha (non-covetousness). Ahimsa is perfect harmlessness and positive love also. This removes the brutal nature in man and strengthens the will.

The scientific basis of the Yama instructions may be explained in this way.

The five directives of Yama lay down behavioral norms as prerequisites for elimination of fear and angst and contribute to a tranquil mind. Nonviolence (ahimsa), truthfulness (satyavachana), non-stealing (astheya), child-like behavior (brahmacharya), and moderation in setting goals (aparigraha), prevent situations that evoke fear in human interactions and contribute to peace of mind.

Ahimsa (non-violence) helps to avoid conflicts with fellow human beings that normally occur because of competition for eating and mating. Hurting a person physically or mentally leads to fear of retaliation which disturbs peace of mind.

Satyavachan (truthfulness) helps peace of mind by eliminating fear of discovery of lies. Untruth implies maintaining two versions of an event, possibly in the same set of neurons, thus causing confusion and mental disturbance.

Astheya (non-stealing) eliminates the anxiety of discovery of theft, potential reprisal by the owner and/or punishment by state. Brahmacharya (celibacy or stage of life devoted to seeking knowledge) averts conflict associated with search for mates, eliminates fear of strife, enhances scholarship and upgrades equanimity.

Aparigraha (moderation in setting goals) prevents angst of potential failure, promotes self-control and poise.

Niyama

Niyama is observance of five canons: Shaucha (internal and external purity), Santosha (contentment), Tapas (austerity), Svadhyaya (study of religious books and repetitions of Mantras), and Ishvarapranidhana (self-surrender to God, and His worship).

He who practises meditation without ethical perfection, without the practice of Yama-Niyama cannot obtain the fruits of meditation. Purify your mind first through the practice of Yama-Niyama. Then practice regular meditation. Then you will attain illumination.

Science underslying Niyama can be presented as follows.

Niyama unlike Yama prescribes mental exercises to train the mind to control emotions: (Saucha), (Santosha), (Tapaha), (Svadhyaya) and (Ishwara pranidhanani).

Saucha (Purity of thought) requires active monitoring of the mind from being obsessed with material or corporeal desires.

Santosha (Contentment) prevents desire to obtain, experience and /or accumulate objects of pleasure.

Tapaha (Austere or ascetic life style), by practicing self-denying and austere life style controls fondness for desire-generated emotions.

Svadhyaya (Study about self) enlightens the true nature of human nature and facilitates healthy thoughts.

Ishwara pranidhanani (Surrender of ego to God) makes it easier to be not self-centered by aiming at higher goals.

Thus Niyama instructions prepare the mind to control animal (reptilian brain- generated) and human (cerebral) emotions.

Asana

Any easy, steady, comfortable pose is Asana. Asanas steady the body. Posture is mastered by releasing tension and meditation on the unlimited.

Asana and Pranayama recognize the intimate connection between body and mind. Asana are a series of gentle physical exercises designed to keep muscles in tone, joints supple and nerves in tune.

Pranayama

Pranayama checks the outgoing tendencies of the mind. It is often misunderstood for breathing exercises. Prana means life force, while yama means to gain control.

Pranayama is the prelude to concentration of mind. Pranayama brings the involuntary breathing cycle under voluntary control by regulating inhalation, exhalation and holding breath static either in the lungs or out of them for periods which could be long or short. Active regulation of breathing naturally requires concentrating on the process, a prelude to control of thinking process the final goal of Raja yoga.

Pratyahara

Pratyahara gives inner spiritual strength. It removes all sorts of distractions. It develops will-power.

The objective of Prathyahara is to disrupt the communication from the sense organ to the brain. Light, sound, smell etc. stimuli received by the sense organs are blocked from the brain centers and thus could not distract from concentration of the mind.

Dharana

Real Yoga starts from concentration. Concentration merges into meditation. Meditation ends in Samadhi. Retention of breath, Brahmacharya, Satvic (pure) food, seclusion, silence, Satsanga (being in the company of a guru), and not mixing much with people are all aids to concentration. Concentrate on Trikuti (the space between the two eyebrows) with closed eyes is preferred. The mind can be easily controlled, as this is the seat for the mind.