When you sit in the full lotus position, your left foot is on your right thigh and your right foot is on your left thigh. When we cross our legs like this, even though we have a right leg and a left leg, they become one. The position expresses the oneness of duality: not two and not one. This is the most important teaching: not two, and not one. Our body and mind are not two and not one. If you think your body and mind are two, that is wrong; if you think that they are one, that is also wrong. Our body and mind are both two and one.