In Wu-Chi all four of the following aspects must be trained to develop the art.
Hand: The hand is used with the Wu-Hsing actions for hitting, and touches as far as the arm will reach, (1 meter).
Voice: The voice is used to startle your opponent, giving you a split second advantage in combat; and reaches far across a valley or as far as you are able to project it (1,000 metres).
Eyes: The eyes are used for concentration, it can reach further than the voice, and can see detail by day and distance by night (10,000 metres).
Mind: The mind can touch, reach, and see where the eyes cannot (infinite), and is used to combine and co-ordinate the efforts of hand, voice and eyes altogether.