Your clarification made it clearer that "norms of life" in fact comes to us naturally. So even without knowing 10 commandments we naturally avoid killing a member of the same group and term it as taboo. 10 commandments are actually written taboos. Which I have previously commented that "follow the norms of life and your'e good to go".
That's actually a good example to clear out the norms of life.
"Norms of life" -- not omnipotent. Sometimes, Following the norms of life are clouded by neural impulse or what we commonly known as emotion. Driven by the compulsive sexual desire would result to a forced intercourse, they know that it is wrong to do such a thing but they do it anyway. Subject gets preggy and then offered to abort. There was actually a psychologicals studies that most *******t rape victims change their attitudes about their unborn child from something repulsive to someone who is innocent when given proper support.