A surgical cutting and fastening instrument is disclosed. According to various embodiments, the instrument includes an end effector, a main drive shaft assembly, and a handle. The handle comprises a gear drive train connected to the main drive shaft assembly, a motor for actuating the gear drive train, and a firing trigger. Retraction of the firing trigger actuates the motor. Further, the firing trigger is connected to the gear drive train such that the loading force applied to the firing trigger is related to the loading force experienced by the cutting instrument in the end effector.