The Lord is life itself. We are recipients of life. We give life unique forms because of our unique shapes as receptacles, and through free will we can choose how fully we will receive life. But we don't have life of our own. It follows from this that the more we turn toward the Lord and receive life, the more alive we will be; and the more we turn away the more dead we will be. It also follows that believing life is our own – with all the loves, the thoughts and the power that entails – is actually the antithesis of life.

This is the state of those in the deepest hells, who reject everything of the Lord, even His existence, and claim all life as their own. They are, in fact, only alive because the Lord forces life on them in the amount necessary to sustain existence.

This is, in a sense, what is represented by the rib – which is human, and is alive, but only in the most limited way. When the people of the Most Ancient Church (Adam) wanted to lead themselves and sense life as their own, the Lord had to use that most dead aspect of them to grant their wish. He had to use that bone, which represents our most hellish potential, what we would be if we were to reject the Lord completely.

But then the Lord did something miraculous. He turned that bone into living flesh, into a new person: the woman Eve. This represents that the Lord built that most dead, most hellish aspect of us up into something which felt life as its own, but could acknowledge that life actually came from the Lord, and could thus again be a recipient of life. It wasn't quite as pure as before; people could no longer commune directly with the Lord. But they had what they wanted instead: a sense of self.

The Writings call this – both the rib and the woman – by the Latin word proprium, essentially meaning "as of self." The rib represents the proprium on its own, which is hellish. The woman represents the proprium given life by the Lord.

(Референци: Arcana Coelestia 151, 152, 153, 154, 155)

In general, trees represent the deepest and most significant intellectual concepts: the ones that come to us most directly from the Lord. This varies depending on us and our states: the people of the Most Ancient Church, who were in a state of loving the Lord, understood truth automatically and internally through what the Writings call "perception"; people in lower states (including most of us) have to work a little harder to learn it from the Word and by willing to follow the Lord. In other parts of the Bible, especially in the prophets and New Testament parables, the meaning of "tree" is broader, meaning not just a person's intellectual concepts but the whole person.

'Trees,' as in Joel 1:10-12, signify knowledges.