The Society of Christian Doctrine, better known as MUSEUM, is a society of Catholic lay volunteers, made of men and women, teaching catechism in the Christian faith formation of children and adults. The society was established by George Preca in March 1907, in Malta. It has eventually spread around the world, first among Maltese migrants in Australia, then in Albania, in North Sudan, and other countries.

George Franco Preca, T.OCarm was a Maltese Catholic priest, the founder of the Society of Christian Doctrine and a Third Order Carmelite. Pope John Paul II dubbed him "Malta’s second father in faith".