St. Thomas Aquinas states that “Law is an ordinance of reason for the common good, decreed by the authorities in charge of the community”. It becomes a rule of conduct and a frame within which man acts. From the above definition it can be noted that other issues like justice, rights and duties derive from the enacted laws. Law is never a univocal term this being the reason why its uses vary from one face to the next.
A univocal term is that whose prediction cannot be taken to mean something else apart from itself. Laws are of different levels, for example, eternal law, scientific laws, ecclesiastical laws, positive laws, civil laws and so on and so forth. However, eternal law is the supreme source of all other laws, or else, all other laws are in participation of the divine or eternal law. God, as the author of creation, cannot be exempted with being the rationale behind the laws enacted to aid man in his actions and endeavors. The caution to act in a manner which tends towards the common good, therefore, is not a creation of the state but it is there, in God’s will for creation. It is believed that laws are for man and not man for the law. This assertion is based on fact that man is a moral and a rational being. S/he should not be enslaved by these laws due to his rational disposition and freedom of the will.
 Aquinas, Thomas. “Summa Theologiae” Thomas Aquinas: Selected Writings. Ed. Ralph Mcinerny. London: Penguin, 1998, p. 307