1515. I once perceived the sphere of the stench of a woman who afterwards entered into association with sirens, and for a period of several days that stench emanated from her wherever she went. The spirits said the stench appeared to be deadly, though she herself did not perceive it at all. The stench of the sirens is similar because their interiors are filthy, but their exteriors are for the most part attractive and good looking. Such have been described in 831. It is a remarkable fact that in the next life sirens mentally take in everything there, and have a better knowledge than others have of the nature of things, even matters of doctrine. But they take everything in to the end that they may turn it into magic and give themselves dominion over others. By a presence of good and truth they enter into good people's affections, but their own dispositions remain such as they were before. From this it becomes clear that a matter of doctrine has no value at all unless a person so becomes what it teaches, that is, unless he keeps life as the end in view. There are in addition many among the inhabitants of hell who have been more expert in matters of doctrine than anybody else. But those who have led charitable lives are all in heaven.