You can only know what it is to be healthy if you have experienced being in poor health. The functions of the brain are also understood by looking at patients with abnormal brains. This is a way of thinking that goes to the center from the periphery.
什麼是健康，要從你是不是不健康才知道，腦的功能也就是從腦異常的病人來理解，這是從周邊進入中心的方法、思考模式。