Principia College is a private liberal arts college in Elsah, Illinois. It was founded in 1912 by Mary Kimball Morgan with the purpose of "serving the Cause of Christian Science." "Although the College is not affiliated with the Christian Science Church, the practice of Christian Science is the cornerstone of campus life."

Christian Science is a set of beliefs and practices which are associated with members of the Church of Christ, Scientist. Adherents are commonly known as Christian Scientists or students of Christian Science, and the church is sometimes informally known as the Christian Science church. It was founded in 1879 in New England by Mary Baker Eddy, who wrote the 1875 book Science and Health with Key to the Scriptures, which outlined the theology of Christian Science. The book became Christian Science's central text, along with the Bible, and by 2001 had sold over nine million copies.