A method of actuating a well tool utilizing first and second pressure sources includes the steps of: placing an actuator chamber in communication with the first pressure source, thereby displacing a piston from a first position to a second position; and then placing another chamber in communication with the second pressure source, thereby displacing the piston to a third position. A multi-position actuator includes an operating member which displaces to operate a well tool, a first position of the operating member corresponding to a pressure source being in communication with a chamber and another pressure source being in communication with another chamber, a second position of the operating member corresponding to the same pressure source being in communication with both of the chambers, and a third position of the operating member corresponding to the pressure sources being connected to the chambers oppositely to that of the first position.