what exists. For the existence of a thing is the cause and source of our knowledge, whereas eternal knowledge is the cause and source of what exists. If, when something came into existence after not existing, additional knowledge arose in eternal knowledge—as happens with temporally originated knowledge—eternal knowledge would necessarily be an effect of what exists rather than its cause. Thus, no change can occur there of the kind that occurs in temporally originated knowledge.

This error arose only from drawing an analogy between eternal knowledge and temporally originated knowledge, reasoning from the observable to the unobservable. The invalidity of this analogy is already known.

Just as no change occurs in an agent when an effect of its action comes into existence—I mean a change that was not present beforehand—so no change occurs in eternal knowledge when its effect comes into being.

This difficulty is therefore resolved. Nor must we conclude, as was thought to follow from that statement, that if no change occurs there—that is, in eternal knowledge—He does not know what exists as it is at the moment it comes into being. All that follows is that He does not know it through temporally originated knowledge, but only through eternal knowledge. For the occurrence of change in