The eye of a hurricane is a zone of calm. The body of a hurricane is a whirlwind of power. Without either the hurricane would not be a hurricane. Separating the eye and body of a hurricane is the boundary layer that also serves to unite them. Without the boundary layer to separate them, eye and body would coalesce and lose their distinctiveness. Without the boundary layer to unite them, eye and body could not function as a unified whole. The boundary layer is defined by both eye and body, being wholly neither.
Using the hurricane as a metaphor, I visualize my mind as the eye of the hurricane, my body as the body of the hurricane and my spirit as the boundary layer that separates and unites both. Spirit is a synergy of mind and body. It facilitates mind/body coordination enabling me to experience correct feeling, my most dependable and powerful state of being.