4531. As it is intelligence and wisdom from the Lord which appear in heaven as light, the angels being therefore called angels of light, so it is the folly and insanity which are from self that reign in hell, causing those who are there to have their name from darkness. It is true that in hell there is not darkness, but a dusky luminosity like that from a coal fire, in which they see one another, and without which they would not be able to live. This luminosity comes to them from the light of heaven, which is turned into such a luminosity when it falls into their insanities, that is, into their falsities and cupidities. The Lord is everywhere present with light, even in the hells, otherwise the infernals would have no capacity to think and thereby to speak, but the light is according to the reception. This luminosity is what is called in the Word the "shadow of death," and is compared to "darkness," and is also turned into darkness with them when they approach the light of heaven; and when they are in darkness, they are in folly and stupidity. Hence it is evident that as light corresponds to truth, so darkness corresponds to falsity, and that they who are in falsities are said to be in "blindness."