Marsilius defines the essential element of law to be coercive force. While a law needs the moral element of jus naturale to be perfect in Marsilius' view, he does not think it necessary for a law to be perfect in order to be a law. A law lacking this moral component may very well be unjust, but Marsilius considers it to be a law nonetheless as it is enacted as law and backed by the coercive force of the state. As long as a law is enforced by coercive force, it is a law in Marsilius' view.

Marsilus does admit that there is a natural law (jus naturale) that can be observed in all places as argued by Aquinas. This law, however, Marsilius rejects as truly being law unless it is enacted as human law by the state and, hence, enforced by the coercive force of the state. Further, despite the fact that natural law (jus naturale) can be observed in all places, not all people understand it. Natural law, then, in the view of Marsilus fails two of Aquinas' criteria for a law to be law, being rational and being promulgated to the whole people. If not everyone understand natural law, as is argued by Marsilius, then it cannot be said that natural law is promulgated to everyone and natural law cannot truly be law. Marsilius also points out that natural law must be accepted on faith rather than being reasoned to and, as such, cannot be a rational measure. Marsilius differs from Aquinas on this because of Marsilius' distinction of faith and reason being entirely separate that Aquinas does not share.

Divine law, in the view of Marsilius, shares the same cardinal problem as natural law, it is not presently enforced by coercive force. Divine law, per Marsilius, is entirely concerned with a future judgment and has no temporal enforcement. Marsilius raids the Christian scriptures to prove his point and cites Jesus' explanation to Pilate of His kingdom being yet to come and Jesus' submission to the Roman authorities to the point of death. If divine law were active in the present world, Jesus would not have submitted to the coercive force of the secular state, nor would Jesus have pointed out that his kingdom was yet to come.

Marsilius also points out that our everyday observations point to the fact that God does not enforce divine law in this world. Marsilius suggests that people commit many immoral deeds in this world and are not punished by coercive force except where their immoral deeds violate the civil law as well as the divine law.