symbol of artistic or intellectual aloofness, by 1889, from French tour d'ivoire, used in 1837 by critic Charles-Augustin Sainte-Beuve (1804-1869) with reference to the poet Alfred de Vigny (1797-1863), whom he accused of excessive aloofness.
Et Vigny, plus secret, comme en sa tour d'ivoire, avant midi rentrait. [Sainte-Beuve, "Pensées d'Août, à M. Villemain," 1837]
Used earlier as a type of a wonder or a symbol of "the ideal." The literal image is perhaps from Song of Solomon [vii:4]:
Thy neck is as a tower of ivory; thine eyes like the fishpools in Heshbon, by the gate of Bathrabbim: thy nose is as the tower of Lebanon which looketh toward Damascus. [KJV]
late 14c., translating Latin artes liberales; the name for the seven attainments directed to intellectual enlargement, rather than immediate practical purpose, and thus deemed worthy of a free man (liberal in this sense is opposed to servile or mechanical). They were divided into the trivium — grammar, logic, rhetoric (see trivial) — and the quadrivium — arithmetic, geometry, music, astronomy. Explained by Fowler (1926) as "the education designed for a gentleman (Latin liber a free man) & ... opposed on the one hand to technical or professional or any special training, & on the other to education that stops short before manhood is reached."
The study of [the classics] is fitly called a liberal education, because it emancipates the mind from every narrow provincialism, whether of egoism or tradition, and is the apprenticeship that every one must serve before becoming a free brother of the guild which passes the torch of life from age to age. [James Russell Lowell, "Among my Books"]