ivory tower

[AAllan at AOL.COM]

Has this been discussed before? I got an inquiry about "ivory tower" and find
the explanations unsatisfying. The dictionaries cite a French source without
explaining why it should be ivory. Charles Earle Funk, in "Heavens to Betsy,"
gives the exact source in French and English but still does not say why it's
ivory.

Funk: "When Charles-Augustin Sainte-Beuve, French literary critic of the
early nineteenth century, coined this term he thought of it as applicable to
the aerie of a poet, a place where he could retire from the world, a retreat.
The term occurs in his own poem, Pensees d' Aout, written in October, 1837. .
. ."

But why ivory?

- Allan Metcalf