In the Catechism of the Catholic Church is found this description of mortal sin: “For a sin to be mortal, three conditions must together be met: ‘Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.’” According to the Catechism, “Grave matter is specified by the Ten Commandments.”
Sa "Catechism of the Catholic Church", matatagpuan ang kahulugan ng mortal na kasalanan, "para masabing mortal ang kasalanan, mayroong tatlong batayan: - Masasabing mortal ang kasalanan kung ito ay lubhang mabigat at ginawa ng buong kaalaman at sinadya."