  If the other spirit in question is God, an omnipresent being, then perhaps his perception can be used to guarantee a completely continuous existence to every physical object. In the Three Dialogues, Berkeley very clearly invokes God in this context. Interestingly, whereas in the Principles, as we have seen above, he argued that God must exist in order to cause our ideas of sense, in the Dialogues (212, 214–5) he argues that our ideas must exist in God when not perceived by  us.[20]   If our ideas exist in God, then they presumably exist continuously. Indeed, they must exist continuously, since standard Christian doctrine dictates that God is unchanging. 