Patanjali
Patanjali was an Indian philosopher, saint, and teacher traditionally thought of as the person who gathered and systematized the teachings of meditation and yoga. He is credited with composing the 2nd century Sanskrit volume of Yoga Sutras from which the modern practice of yoga is derived. It is a major work containing aphorisms on the practical and philosophical wisdom regarding practice of Raja yoga. (“Yoga” in traditional Hinduism involves rigorous meditation practice, ethics, metaphysics, and devotion to the One.)
“Patanjali gives a beautiful analogy to explain how God is attained through yoga. Our mind, he says, is like the surface of a pond. Just as we cannot see the jewel lying at the bottom of the pond because of the breeze disturbing its surface, we do not see the divine in us because our mind is in constant agitation. If the surface of the pond is undisturbed, one can see the jewel at the bottom. So also, if the mind is kept calm, with the doors to the external world closed, one can see God within.” http://profiles.incredible-people.com/patanjali/
Virtually nothing is known about the life of Patanjali.
He is also supposed to be the writer of a work on Ayurvedic medicine.