the terms ‘vertical and horizontal time’ derive from symbolic interpretations of the crucifixion, where Eternity, embodied in Christ as the Son of God, intersected the ‘horizontal’ movement history, that is, the death of one human being.
Pollack establishes ‘horizontal’ as the plane of ordinary historical time and physical existence, constitutively defined by its contrast with the vertical dimension of eternity, with the cross as the archetypal image of their meeting.
, Seventy-Eight Degrees of Wisdom: A Tarot Journey to Self-Awareness, 1980thesis