There seems to be but one way. The attended-to idea does not exclude every other idea, but it does exclude the opposite idea, and opposite to each other is here again that pair of ideas which lead to opposite actions, to opposite psychophysical attitudes. We must remember here the psychomotor character of our brain processes which we so fully discussed. We recognized the fundamental truth that there is no sensorial state which is not at the same time the starting-point for motor reaction. We recognized that the brain is by its whole psychological development a great switchboard which transfers incoming currents into outgoing ones and that its biological meaning lies in the fact that it is the center piece of an arc which leads from the sense organs to the muscles. We cannot conceive of those relations as complex enough; we know, of course, that millions of nerve fibers lead from the periphery to the highest psychophysical apparatus in the cortex of the brain and that millions of fibers bring about the interrelation between these central stations, but we must never forget that millions of fibers also represent the outgoing paths and that they too lead down to lower central motor instruments which are again in numberless corelations. Any impression is thus a starting point for attitudes and reactions and it is an empty abstraction to consider it otherwise. An idea is never, psychophysically considered, the end of the process, it is always also a beginning. No external action may follow, but the mental impulse to such is nevertheless starting in the highest center.