Find accurate definitions of over 5,000 Catholic terms and phrases (including abbreviations). Based on Fr. John Hardon's Modern Catholic Dictionary, © Eternal Life. Used with permission.
Name of the axiom of Pope St. Celestine I (422-32), "Legem credendi statuit lex orandi" (The rule of prayer determines the rule of faith). By this is meant that the Church's liturgy is the most effective means of preserving and interpreting the true faith.