A surgical cutting and fastening instrument (10) is disclosed. According to various embodiments, the instrument includes an end effector (12) comprising an elongate channel (22), a clamping member (24) pivotably connected to the channel, and a moveable cutting instrument (32) for traversing the channel to cut an object clamped in the end effector by the clamping member when the clamping member is in a clamped position. The instrument comprises a main drive shaft assembly (48) for actuating the cutting instrument in the end effector, a gear drive train (66) connected to the main drive shaft assembly, and a motor (65) for actuating the gear drive train. The instrument also includes a closure trigger (18) and a firing trigger (20), separate from the closure trigger, for actuating the motor when the firing trigger is retracted. Also, the instrument comprises a mechanical closure system connected to the closure trigger and to the clamping member for causing the clamping member to pivot to the clamped position when the closure trigger is retracted.
