The mind is a complex of interacting elements.
The stranger is close to us, insofar as we feel between him and ourselves common features of a national, social, occupational, or generally human, nature. He is far from us, insofar as these common features extend beyond him or us, and connect us only because they connect a great many people.
控制的目的是使系统在存在不确定性和干扰的情况下仍能按期望的方式运行。
