428. As the world of spirits is an intermediate state between heaven and hell with man, so it is an intermediate place with the hells below and the heavens above. All the hells are shut towards that world, being open only through holes and clefts like those in rocks and through wide openings that are so guarded that no one can come out except by permission, which is granted in cases of urgent necessity (of which hereafter). Heaven, too, is enclosed on all sides; and there is no passage open to any heavenly society except by a narrow way, the entrance to which is also guarded. These outlets and entrances are what are called in the Word the gates and doors of hell and of heaven.