Man, alone in the animal
kingdom, stands upright, so the vertical line represents the physical
symbol of the number One, man striving toward spirit. This simple line
is the basic shape of the World Tree or Axis Mundi
that connects the Heavens, the Earth and the lower regions. It is not
only a basic phallic symbol but also signifies the soul that strives for
union with the Divine.
The upright line tells us where we are at a precise
moment; think of the big hand of the clock, vertically oriented at 12
o’clock.