Spiritual Meaning:
Spiritually a single column has the same significance as a tower, a structure to enable us to reach the heavens or the Divine. It may be an object of worship or a memorial. A column of light denotes an awareness of spirit or spiritual energy. Boaz (strength) and Joachim (beauty) are the two columns which stood at the entrance to King Solomon’s temple in Jerusalem.

Psychological / Emotional Perspective:
Single columns could represent strength or single mindedness. Two  stone columns in the distance indicate a doorway to the future or a way into the unknown.

Everyday Material Aspects:
A column will suggest the penis but also masculinity. It is also structural or emotional support.

You might like to consult the entry for Pillar for further clarification.