This question of a belief system is very important to many people, but to us here in yoga what is important is that you find out for yourself. You don't begin the practice of yoga and meditation with a belief system. That is the difference between a religion and a science. In a religion you must believe first and practice afterwards. You declare your belief, and then you start practicing your religion. In a science, on the other hand, you practice first and believe afterwards. When you go to a research lab to take a course in chemistry of physics, you don't stand there at the door and cross yourself and say, "I declare my belief that water is H-2-0." No, you walk in there, without declaring any kind of belief; and your chemistry professor or physics professor says, "Take this flask, and connect this here, and do this there, and boil it here this way, and so on and so forth;" and then you see that water is indeed H-2-0, and you believe.