Five solae

The five solae (from Latin, sola, lit. "alone"; occasionally Anglicized to five solas) of the Protestant Reformation are a foundational set of Christian theological principles held by theologians and clergy to be central to the doctrines of justification and salvation as taught by the Calvinism and Lutheranism branches of Protestantism, as well as in some branches of Pentecostalism. Each sola represents a key belief in these Protestant traditions that is distinct from the theological doctrine of the Catholic Church, although they were not assembled as a theological unit until the 20th century. The Reformers are known to have only clearly stated two of the five solae. Even today there are differences as to what constitutes the solae, how many there are, and how to interpret them to reflect the Reformers' beliefs.