[quote:2lngk6lf]I thought nothing was a mortal sin unless you had knowledge, free will to perform the act and if it was grave.

If one does not know sex before marriage is wrong how can it be classified as a mortal sin?[/quote:2lngk6lf]

That is certainly how I understood it.

[color=green:2lngk6lf][b:2lngk6lf]1857[/b:2lngk6lf] 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.”131

[b:2lngk6lf]1858[/b:2lngk6lf] Grave matter is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: “Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother.”132 The gravity of sins is more or less great: murder is graver than theft. One must also take into account who is wronged: violence against parents is in itself graver than violence against a stranger.

[b:2lngk6lf]1859[/b:2lngk6lf] Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart133 do not diminish, but rather increase, the voluntary character of a sin.

[b:2lngk6lf]1860[/b:2lngk6lf] Unintentional ignorance can diminish or even remove the imputability of a grave offense. But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man. The promptings of feelings and passions can also diminish the voluntary and free character of the offense, as can external pressures or pathological disorders. Sin committed through malice, by deliberate choice of evil, is the gravest. [/color:2lngk6lf]