Yoga philosophy is one of the important branches among six schools of philosophy. It is philosophy which deals with mental and physical levels. It can develop mental and spiritual aspects of a human being. Hence it is a practical science. The ultimate aim of philosophy is to acquire knowledge and realize the absolute truth.
Maharsi Patanjali in his yogasutra divided the subject into four padas, i.e. Samadhi pada, Sadhana pada, Vibhuti pada and Kaivalya pada. In his text, Patanjali has discussed the topic yoga from the very beginning. It is he who the first time scientifically discusses about the functions of mind and how it can be controlled. For that he has offered various ways and means.
Patanjali describes about the astanga yoga. In yoga philosophy, Yama, Niyama, Asana, Pranayama. Pratyahara, Dharana, Dhayana and Samadhi are called astangas. These eight paths are the subject of Vivekakhyati. It is very much essential for yoga. Yama and Niyama destroy the rough attitude of a man. Pranayama can be static through Asan. The consistency of the Pranayama helps to achieve Pratyahara, Avidya, Asmita and Klesa etc, which are destroyed in Dharana, Dhyana and Samadhi. The yogis generally move through these states.
Before describing the principles of yoga, Patanjali speaks of consciousness and the restraint to its movements. The verb ‘iit’ means to perceive, to notice, to know, to understand, too long for, to desire and to remind. As a noun, ‘iit’ means thought, emotion, intellect, felling, disposition, vision, heart, soul and Brahman. Chinta means disturbed or anxious thoughts, a chintana means deliberate thinking. Both are facets of chitta. As they must be retraining through the discipline of yoga, yoga is defined as ‘chittavrutti nirodhah’. A perfectly subdued and pure chitta is divine and at one with the soul. Patanjali begins the treatise of yoga by explaining the mind. So that we may learn to discipline it, and intelligence, ego and consciousness may be restrained. Subdued and diffused, then drawn towards the care of our being and observed in the soul. In yogasutra, Patanjali explains that painful, painless and imprints those are gathered by fine means. Pramana or direct perception, which is knowledge that arises from correct through right perception. Viparyaya or misperception is a misconception, leading to contrary knowledge, vikalpa or imagination or fancy, Nidra or Sleep and Smriti or Memory. These are the fields in which the mind operates and through which experience is gathered and stored.