If souls can't split,it can only follow one half of the brain, and that's why we'll get somebody that's got one half, sometimes the other half,but never both halves.

如果灵魂不能分割，只跟随一半大脑，才能有只有其中一个得到半个大脑的人存活，而没有两人同时存活的状况。

耶鲁公开课 - 死亡课程节选