The word daemon comes from the greek daimon (δαίμων) and can mean "spirit" or "divinity". The Catholic Church has inherited much of Greco-Roman paganism, in epoch, to please the new followers. With the Councils there was much adaptation. And the word demon meant the supreme leader of evil. Well, in the Middle Ages this idea was used to dominate the faithful by fear, for the same pay the tithe. The only supreme leader is God.