We can see from the experience of Odin that the image of the tree was the template within which all of the sacred world could be apprehended. The tree was the framework within which one "flew" to these Otherworlds. And since the exploration of sacred space was also a quest into the nature of human consciousness, the tree was regarded as an image of the ways in which we, humans, are constructed psychically. It was a natural model for our deepest wisdom, our highest aspirations.