4860. CONCERNING GENII AND THEIR HELL. I was let down, with certain spirits, into a certain hell of genii which is at the back; but it was then granted me to see but little; for it was dangerous for the sight to be opened, because, in this way, their operations - which are most hurtful because they are not into the very matter of the thought, but into the affections thereof - would at once inflow. This it was granted me to see. There were walls, as of a great building, but without roof and without windows. In place of windows are great openings. It was said, there, that they cannot dwell in houses that have roofs and windows, and that, in case they do, they experience tightness, as if they are being suffocated. The reason is, because windows signify those things which are of thought, and roofs its upward limit.