a vertical axis (between the superior function and inferior function), which I think of as the ‘spine’ of consciousness defining the person’s conscious standpoint, and a horizontal axis (between the auxiliary and tertiary functions)
Beebe defines the vertical axis as the foundational ‘spine’ of typological consciousness, running between the superior and inferior functions and establishing the individual’s core psychological standpoint.
, Energies and Patterns in Psychological Type: The Reservoir of Consciousness, 2017thesis