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Principia School

Celebrating 125 Years of Progress

Since 1898, Principia School has been committed to cultivating students who think fearlessly, live selflessly, and learn purposefully. Principia’s focus is the “education of the whole (person)–physically, mentally, socially, and spiritually, as well as intellectually.” (EAP, page 69) Serving students from infancy through grade 12, Principia School is a student-centered, future-focused coeducational day and boarding school grounded on the teachings of Christian Science, welcoming students from a variety of faith backgrounds. 

Dive into Principia’s past, present and future. Hear about the people and events that made Principia what it is today.

A Few Historical Highlights

  • Principia has been a destination and home for International students since its second year in 1899. Today, 23% of our Upper School student body hails from around the globe. 

  • There has been a Girls’ basketball program at Principia since 1901. We were one of the first schools to introduce a women’s athletic program (1920) led by a woman athletic director.

  • In 1906 Principia graduated its first Upper School class. Since then, there have been 110+ classes to walk across the stage and accept their diplomas. 

  • Principia Upper School was officially accredited by University of Missouri in 1914 and accredited by North Central Association in 1915. 

  • After nearly 50 years on the Page Avenue campus, the school moved to its current 360 acre location in 1956-1960.

  • Education at The Principia, a collection of letters and inspirational talks given by Principia’s founder, Mary Kimball Morgan, was published in 1965. It continues to spark thought and encourage the growth of Principians to this day. 

  • Construction of Ridgway Auditorium began in 1977 to provide a robust and beautiful space for the Performing Arts program. 

  • 22 Apple II computers were acquired for the St. Louis campus in 1981 and launches a commitment to continued investment in state-of-the-art technology for its students. 

  • The boy’s baseball team took the state championship in 1990, a first-ever in that sport. 

  • Principia hosted the first Mediation Tournament for high schoolers in the nation in 2020 in partnership with the International Academy of Dispute Resolution (INADR).

  • Our commitment to sustainability is award-winning. Principia has been nationally recognized by the US Department of Education as a Green Ribbon School.

Looking to the Future

  • Two state-of-the-art Smart (STEM) labs were recently added to the School for students K–12, with 10+ STEM projects completed each semester. 

  • Construction has recently been completed on our 87,000 square foot Simon Field House which includes performance and practice courts, an indoor track, fitness and event rooms, and more! 

  • We recently renovated our eight athletic fields on campus.

Our Story

A mother. Two young boys (make that three, with a friend). An earnest desire to promote children’s moral and spiritual progress alongside their academic growth—and a commitment to Christian Science.

From these seeds sprang the idea and institution that is Principia today.

Back in 1897, when Christian Science practitioner Mary Kimball Morgan began educating her two young sons at home, she wasn’t setting out to establish a school. Word spread quickly, however, among the thriving community of Christian Scientists in St. Louis, and by the next year, 15 students were enrolled in “Mrs. Morgan’s school.”

Soon, the group moved from the Morgans' carriage house into a two-room storefront, and a second teacher was hired. Even more students started attending. And that's how—without fanfare, but with a firm foundation in the teachings of Christian Science—Principia officially began in 1898. Progress and growth followed quickly:

  • The first high school class graduated in 1906.

  • In 1910, the four-year program expanded to six years, resulting in one of the first junior colleges in the nation.

  • In 1934, Principia’s new four-year liberal arts college, established across the Mississippi River in Elsah, Illinois, graduated its first class.

  • By 1960, all levels of the School had moved to the current campus in St. Louis. 

Today, across both campuses, Principia enrolls hundreds of students from coast to coast across the United States and from many other countries around the world.

Kimball Family

Education at The Principia

The educational values and approaches that first prompted Mary Kimball Morgan to homeschool her sons and led, eventually, to the Principia of today are set forth in Education at The Principia, a collection of talks, letters, and other writings Morgan shared over the years. The volume has provided generations of students, parents, teachers, staff, and administrators with practical, spiritually-based insights into the great responsibilities and grand possibilities of education.  

The book addresses a range of subjects including educational reforms, parenting, spiritual approaches to discipline, teacher-student relationships, and the development of character. Though some of the talks and writings date back more than a century, their message remains timely and relevant.

Education at The Principia