80. He is permitted by every perception that is from the Lord to become aware of what good and truth are, but not to do so from himself or from the world, that is, to probe into mysteries that are part of faith by means of sensory evidence and factual knowledge which cause the celestial in him to die, verses 16-17.

Bones are strong and supportive, providing a framework for our bodies and making motion and action possible. They are also the least "alive" part of our bodies, with much of their structure made up of a mineral matrix. As such, they represent a strong, supportive, functional but innately nearly dead part of our spiritual makeup: the "proprium."

The proprium is the part of us that feels life as our own, that perceives our loves and our thoughts as originating within ourselves. If we simply follow the proprium without looking to the Lord, it will lead us to a hellish state, in which we believe ourselves to be all-powerful and deny the existence of the Lord altogether.

Bones, on their own, will go dry, brittle and completely dead. If, however, we acknowledge the Lord and follow him, that's like putting flesh on the bones and being alive. In that case the bones – strong, supportive, protective and as alive as they can be – represent the proprium in relation to intellect, the part of us that perceives our thoughts as our own but turns them toward the Lord.