Like justness in a judge's decision, or beauty in a painting, soul is a quality of absoluteness in something relative. Understood profoundly, people are connected to the holiness of the world in such a way that they reveal a dimension of holiness in themselves, a dimension of depth that is absolute.
It is strange how much we resist the inherent peace and quiet that is always possible. Perhaps this is because resting in simple presence is so foreign to a lifelong habit of mental complication, and we may have confused complication with a sense of aliveness. We may assume that having no particular mental project would result in boredom. Or we may be overwhelmed by how vast and free life suddenly feels when our minds are not on the hunt.