The earliest seeds of yoga are found in the Rigveda (c. 1500 BCE), where the word "yuj" — to yoke or unite — first appears. The Upanishads deepened the philosophy of inner union. Around 400 CE, the sage Patanjali codified the entire science into 196 aphorisms — the Yoga Sutras — a text so precise it reads like a manual for the human mind.

• Yama — ethical restraints: non-violence, truth, non-stealing, celibacy, non-possessiveness
• Niyama — personal observances: purity, contentment, discipline, self-study, surrender
• Asana — physical postures to prepare the body for stillness
• Pranayama — mastery of the life-force through breath
• Pratyahara — withdrawal of the senses inward
• Dharana — single-pointed concentration
• Dhyana — unbroken flow of meditation
• Samadhi — the state of complete absorption and union

The Bhagavad Gita reveals that yoga is not one path but many. Jnana Yoga is the path of discernment and wisdom — of asking "Who am I?" until only truth remains. Bhakti Yoga is the path of devotion, dissolving the ego through love of the Divine. Karma Yoga is the path of selfless action — working without attachment to results. Raja Yoga, the royal path, is Patanjali's eight-limbed system of meditation. Every human temperament has a door.

Modern neuroscience now confirms what ancient seers knew: regular yoga practice reshapes the brain. Studies show increased grey matter in regions governing attention and self-regulation, reduced cortisol, improved vagal tone, and measurable reductions in anxiety and depression. But the rishis were after something deeper — the direct experience of the ground of consciousness itself, what they called Samadhi.