William James (Varieties of Religious Experience 1902) believed that mystical experiences consist of four distinguishing features. They are ineffable, that is they can not adequately be described by the human language. They are noetic; they convey some knowledge of the universe. They do not last long and may only happen once in a life time – transcendent. They are also passive; the person has no control over them. In all religious experiences James identifies a feeling of deep inner peace, joy, great emotional intensity and an unshakeable claim that God has been encountered in a bipolar event.