Yoga Sutra 1.2
Yoga is the restriction of the fluctuations of consciousness. (translation by Georg Feuerstein)
In Yoga Sutra 1.2, Patanjali addresses consciousness. But what is consciousness, and what's it got to do with your yoga practice? Once you understand how it works, you can learn to navigate through life on a more even keel. Citta (pronounced CHIT-ah) has two essential elements, the first of which we'll call "content." Many types of content fill your consciousness—your direct perception of an object or person, a thought or a memory, a feeling, even a dream. These contents parade through citta with hardly a moment's rest. You naturally identify closely with them. They serve as grist for your ego's mill, driving the ups and downs of your daily emotional rollercoaster.
That's where the second element of consciousness comes in. Drashtri (pronounced DRASH-tree), literally "the seer," shines light on the contents of citta. Without it, there would be no consciousness. Imagine yourself in a strange, totally dark room without a flashlight, unable to move and feel your way around. Could you describe the room's contents? Not likely. Similarly, the contents of citta would be hidden from our view without drashtri.
While the citta's contents are ephemeral and in constant flux, the seer is eternal and never changes. It is the perfectly impartial observer; all it does is shine light on the contents, accepting all with equanimity. In Patanjali's view, the seer is your authentic self. Learning to recognize its existence is one of the goals of Patanjali's yoga.
Close your eyes and notice whatever contents are passing through citta. Normally you identify with such contents and are unaware of the seer. Now step back from the contents. Can you identify with the seer? Try this exercise the next time you're in a stressful situation. When you stop identifying with your thoughts and notice the seer, does it diffuse the stress?