What are the seven wisdoms that are apparently represented by the Menorah?
According to Paul Johnson in his "A History of Christianity" (p. 154) they date back to Bishop Isadore in 636.
Seville had already become a gathering place fro scholarly Christian refugess and with the conversion of the Arian court it became possible to build up a centre fo Christian culture. Over a period of twenty years Isadore and his helpers compiled a vast survey of human knowledge, arranged etymologically and incorporating the works and transmission of Boethius and Cassiorodus, and much else.... Almost by accident he founded a civilization, or at any rate an educational system. His work, made public in 636, first describes the seven liberal arts, grammar, rhetoric, dialectic, arithmetic, geometry, music and astronomy; then their dependent arts, medicine, law and chronology; then it moves on to the Bible and its interpretations and the Church's canons and offices.... We have here a summa of human knowledge in which Christian doctrine and teaching and the role of the Church is placed right at the centre of the intellectual universe, and radiates to its most remote corners.... [this] became the basis for all teaching in the West for about 800 years.
Wikipedia actually dates the classification of the liberal arts into their seven categories back to the 5th century.
Clearly the Menorah and Jewish knowledge precedes Christianity and Western education by many centuries. But one can't help but think that perhaps the Rishonim were also partially influenced by the surrounding culture which grouped knowledge into these seven categories.