The Yoga Sutras of Patanjali are one of the six darshanas of Hindu or Vedic schools and, alongside Bhagavad-Gita and Gherand Samhita, are a milestone in the history of Yoga. Yoga-Sutra are a set of aphorisms (sutras), which are short and easy to memorize. They are part of an ancient oral tradition, which means you don't learn by reading and reasoning alone but you listen and chant. Though brief, the Yoga Sutras are an enormously influential work that is just as relevant for yoga philosophy and practice today as it was when it was written.
The title of the Patanjali's work consists of two Sanskrit words: Yoga and Sutra. 'Yoga', as used by Patanjali, refers to a state of mind wherein thoughts and feelings are held in check, and 'Sutra' means thread. It refers to the thread of a mala, upon which the yoga aphorisms are strung like beads. For that reason the title is sometimes rendered in English as the 'Yoga Aphorisms'.
Yoga as a system of thought and practice has a primary reference to the philosophical system that flows from the teachings of the ancient Indian Yoga philosopher, Patanjali. Other great works elaborating on Yoga are the Siva Samhita, the Hath yoga Pradipika and the Gherand Samhita. Shiv Samhita is the fundamental work on yoga, said to originate from Lord Shiva, the founder of yoga. The Gherand Samhita is much more practical. It comprises of seven lessons covering aspects such as asanas (32 of them to be specific), how to perform it and its effects; mudras (25 of them), the control of senses, pranayam (breath control), meditation, and super consciousness. The Hatha Yoga Pradeepika by Swami Swatmarama is a much later text (16th Century) which deals with the pre-requisites of yoga, the asanas, pranayam, mudras, bandhas and Raj Yoga.
The aim of yoga-sutras is to set man free from the cage of matter. Mind is the highest form of matter and man freed from this dragnet of chitta or ahańkāra (mind or ego) becomes a pure being.
The mind or Chitta is said to operate at two levels-intellectual and emotional. Both these levels of operation must be removed and a dispassionate outlook replace them. Constant vichara (enquiry) and viveka (discrimination between the pleasant and the good) are the two means to slay the ego enmeshed in the intellect and emotions. Vairagya or dispassion is said to free one from the pain of opposites love and hate, pleasure and pain, honour and ignominy, happiness and sorrow.
Four Padas (Chapters)
The Patanjali's Yog Sutra provide terse treatment to the complex subject of Yoga and seamlessly covers aspects such as types of yoga, practice of yoga, powers of yoga and the ultimate aim or result of yoga. Yog Sutra deals with the subject matter at a psychological, psychosomatic and metaphysical level.
Patanjali's Yoga Sutra, which outlines the sovereign path of Raja Yoga, is composed of a total of 195 sutras or aphorisms. These sutras are structured around four padas or chapters as follows: