91. Since such is the distinction between the heat and light of the one world and of the other, it is therefore clearly evident that those who are in the one world cannot see those who are in the other world. For the eyes of a man who sees from natural light, are of the substance of his world, and the eyes of an angel are of the substance of his world. Thus in each case they are formed to receive adequately his own light. From these considerations it can be seen from how much ignorance those people think who, because they do not see them with their eyes, do not admit into their faith [the belief] that angels and spirits are men.