Because I have a conscience.
4 seconds sound clip from the Scent of a Woman (1992) movie soundboard.
You can hear this line at 01:14:28 in the Blu-ray version of the movie.
Quote context
[...]
- You sound like a guy in Lives of a Bengal Lancer.
- What do you give a shit for? About what? About whether I blow my brains out or not.
- Because I have a conscience.
- You have a conscience. I forgot. The Charlie Conscience. Do we tell? Do we not tell?
- Do we follow the rich boy's code or not?
- Do we let this blind asshole die or not?
- When were you born, son? Around the time of the Round Table? Haven't you heard? Conscience is dead.
[...]