The positive part of this contention seems to be much less impressive than the negative. The vinculum suhstantiale has the important office of ensuring substantial persistence through a period of time. It is just here that the vinculum spirituale is weakest. If pluralistic pan-psychism is interpreted in the light of human waking experience, sleep and trances seriously perturb the theory of a persistent conscious self. It is difficult not to invoke the persistence of the body.