Patanjali's Yoga Sutras, which are said to be over 5,000 years old, are a great treatise on yoga and one of the deepest forms of psychology in the world today. To explore the future of modern psychology we have only to reach into our ancient past in yoga. The Yoga Sutras are a map for our lives as well as a bridge between eastern and western studies of the human psyche. The teachings of the Yoga Sutras are important because the verses give the reason why we are practicing yoga.