Why does Launcelot want to run away from the Jew? What does his conscience advise him to do?

Lancelot, referred to as a clown, is the servant to Shylock. He tells the audience that he is thinking about running away from his master, whom he describes as a devil. However, he cannot make up his mind about whether to run away or not because his conscience makes him guilty when he thinks about leaving Shylock.