Its objective is to gradually achieve physical and mental self-control and, consequently, concentration of the mind. This mind control facilitates the discernment between matter and spirit that ultimately leads to liberation.

Raja yoga elaborates a range of moral, ascetic and mystical practices in eight (ashta) successive stages (anga), to achieve gradual control of the mind and the “cessation” (nirodha) of the “mental processes” (citta-vrtti ), which is contemplation or enlightenment (samadhi). Unlike jnana-yoga, raja-yoga does not believe that it is possible to achieve enlightenment in a single instant of sudden understanding, but rather that it is first necessary to purify the mind so that samādhi occurs naturally and permanently. According to Patañjali, constant practice (abhyasa) and detachment (vairagya) are necessary to calm the mind. It is a twofold process that accelerates purification and spiritual refinement.

On the one hand, detachment empties the mind and weakens its natural tendency to extroversion; on the other, the practice sits in that mental void to strengthen concentration, internalization and discernment. Both are necessary to achieve a state of calm and alertness. Without detachment, practice is mere exercise; without practice it is difficult for detachment to take hold and not be swallowed up by the innate tendencies of an outgoing mind.

However, Patañjali speaks of a supreme detachment, the fruit of an intellectual gnosis, which is equivalent to the highest knowledge. The practice (abhyasa) is articulated in eight steps (ashta-anga), which make up the so-called ashtanga-yoga. The gradual path of the eight steps is designed to achieve progressive purification of the mind, on the one hand, and the unification of consciousness, on the other. These eight stages collect and systematize different moral, ascetic and mystical practices from the tradition of the renouncers that had developed from the Upanisad to the times of Patañjali, passing naturally through Janinism and Buddhism.

These eight stages can be classified in different ways. B.K.S. Iyengar classifies the eight stages into three groups:

Bahiranga Sadhana

Outward progression [bahir = out, anga = progression]

• 1. YAMA: attitude towards the world
  – Ahimsa: non-violence
  – Satya: truthfulness
  – Asteya: do not steal
  – Brahmacharya: sexual continence
  – Aparigraha: absence of greed or avarice
• 2. NIYAMA: attitude towards oneself
  – Saucha: purity, hygiene
  – Santosha: contentment
  – Tapes: asceticism, austerities
  – Svadhyaya: study of texts and self-inquiry
  – Ishvara-pranidhana: devotion and surrender to the Lord
• 3. ASANA: harmonic body
• 4. PRANAYAMA: breath control

Antaranga Sadhana

Inward progression [= antar

• 5. PRATYAHARA: absorption of the senses, inner attention
• 6. DHARANA: concentration, attention of senses and thoughts in a single object

Antaratma Sadhana

Progression towards the soul [= atma]

• 7. DHYANA: meditation, not concentration, not thought, immediate understanding
• 8. SAMADHI: union, Illumination, fusion of the observer and the observed object