We have two abilities that make up our life, one called will and the other understanding. They are distinguishable, but they are created to be one. When they are one, they are called the mind; so they are the human mind and it is there that all the life within us is truly to be found.
Just as everything in the universe that is in accord with the divine design goes back to what is good and what is true, so everything in us goes back to will and understanding. This is because whatever is good in us resides in our will and whatever is true in us resides in our understanding. These two abilities, or these two living parts of ours, receive and are acted upon by what is good and true: our will receives and is acted upon by everything that is good, and our understanding receives and is acted upon by everything that is true. Goodness and truth can be found nowhere else in us but in these faculties. Further, since they are not to be found anywhere else, neither are love and faith, since love and goodness are mutually dependent, and similarly faith and truth.
Now, since everything in the universe goes back to goodness and truth and everything about the church goes back to good things that are done from love and truth that belongs to faith, and since we are human because of will and understanding, the body of teaching [I am presenting] deals with will and understanding as well. Otherwise we could have no clear concept of them, no solid foundation for our thinking.
Will and understanding also form the human spirit, since they are where our wisdom and intelligence dwell—in general, where our life dwells. The body, [by contrast,] is simply a thing that follows orders.
There is no knowledge more relevant than knowing how our will and understanding make one mind. They make one mind the way goodness and truth form a unity. There is the same kind of marriage between will and understanding as there is between goodness and truth. You may see quite well what that marriage is like from what has already been presented concerning goodness and truth [Sections 23–24]. That is, just as goodness is the reality underlying something and truth is how that thing becomes manifest from goodness, so our will is the reality underlying our life, and our understanding is how life becomes manifest from our will. This is because the goodness that is characteristic of our will takes form in our understanding and presents itself to view [there].
People who are focused on what is good and true have both will and understanding, while people who are focused on what is evil and false do not have will or understanding. Instead of will they have craving, and instead of understanding they have mere information. Any will that is truly human is receptive to goodness, and any understanding that is truly human is open to truth. This means anything that is evil cannot [properly] be labeled “will,” and anything that is false cannot [properly] be labeled “understanding,” because these things are opposites, and opposites are mutually destructive. That is why anyone who is focused on something evil and therefore on what is false cannot be called rational, wise, or intelligent. Then too, the deeper levels of our minds are closed when we are evil, and those levels are where our will and understanding principally reside.
We assume that we have will and understanding even when we are evil because we say that we are willing things and understanding them, but our “willing” is nothing but craving and our “understanding” is mere information.
from New Jerusalem, Sections 28-33