1391. Communications are made both by conversation with one another, and by ideas together with representations; for the ideas of thought of spirits are simultaneously representative, and by this means all things are set forth in great fullness. They can represent more by a single idea than they can utter by a thousand words. But the angels perceive what is within the idea, what the affection is, what the origin of the affection, what its end; besides other things that are interior.