Human beings have two modes of thinking, external and internal. In the natural world they use the external mode, in the spiritual world the internal. These two modes act as one in the case of the good, but not in the case of the wicked. It is rarely possible in the natural world to see what a person's interior is like, since he has learned from childhood to behave well and rationally, and he likes to seem to be so. But in the spiritual world everyone's nature is plain to see, for then he is a spirit, and the spirit is the internal man. Now because I have been allowed to be in that world and see there what internal men from different kingdoms are like, it is my duty, because of its importance, to make this generally known.

* The Latin uses the term equivalent to 'English', but it is clear that the Scots are included; see 812.