Adelphi is an intentional community, founded by the author of the book The Ultimate Frontier. It is a place for those people interested in the philosophy presented in that book to live and interact with others of like mind. The book gives an intelligent explanation of the mysteries of human existence, and provides a practical approach to spiritual growth. Many readers said it tied together the many pieces of their own philosophy they had already learned through living. The book's philosophy is centered on the idea that the purpose of life is personal growth in psychological and emotional maturity. The pursuit of ever-greater maturity is a continuous challenge with great rewards, and it is the ultimate frontier.

The community of Adelphi was formed around The Adelphi Organization, and membership in that organization is required to reside in the community. The Adelphi Organization is a philosophical, educational, non-profit organization, chartered by the State of Texas.

Learning about the community and becoming a member and resident begins with reading The Ultimate Frontier. Interested readers can then visit the Adelphi community and meet the people there, take a five-lesson correspondence course on The Ultimate Frontier, and apply for membership. There are no application fees.

In 2009, Adelphi is a community of members living in permanent, conventional brick homes, all built by members, and located in a rural setting near Dallas, Texas. Some of the homes are privately owned, and most are owned by The Adelphi Organization and rented to members. There are currently rental vacancies and lots available for sale. The community is self-governed by referendum and by a board and committees elected from the membership. All elected persons serve without pay. Buildings and infrastructure are constructed without debt, and are paid for by member donations, rents, and volunteer labor, with additional help from outside donations.

Adelphi is a place where a conscious, deliberate effort to achieve ever-greater maturity is our purpose, and members work to create a culture that supports that goal. Come live, learn, and grow with us.