There are many different types of laws that help to guide and inform the decisions we make. The Church recognizes many levels of law, including the eternal law, divine law, the natural law, and human law. Eternal law is found only in God himself, who is the source of all order and being. Divine Law is what God has revealed to us through Scripture and Tradition, such as the Ten Commandments. Human law consists of laws in our society, like speed limits, and ecclesiastical laws, such as abstaining from meat on Fridays. The natural law is one that is not spoken of as much in our civil discourse today. Natural law is written into the very fabric of living things, and it is our ability to instinctively know right from wrong and to seek good instead of evil.
The natural law is not an invention of the Catholic Church or of any religion in history. In fact, the Catechism quotes Cicero in describing the natural law. He once wrote, “For there is a true law: right reason. It is in conformity with nature, is diffused among all men, and is immutable and eternal; its orders summon to duty; its prohibitions turn away from offense . . . . To replace it with a contrary law is a sacrilege; failure to apply even one of its provisions is forbidden; no one can abrogate it entirely” (CCC 1956). Cicero certainly was not a Christian, yet he spoke about eternal truth and the duty we have as human beings to obey this law.
The natural law is written on our hearts, and we can follow it by using right reason. However, it is possible to ignore the natural law and act contrary to it. Some of the most basic moral laws that all societies enforce are known even to the smallest of children: stealing and murder are evil actions. These principles were not invented out of someone’s imagination and imposed on the rest of society. Rather, we all know within ourselves that these actions are evil, and we also know that legitimate authority should punish people who go against the natural law and disrupt the order of society through murder or theft.
It is hard to have a conversation about what is right and wrong without a sense of natural law. The Catholic Church has long been the most outspoken institution against the legal protection of abortion. Some of her critics say that the Church should not impose her religious beliefs on others. But the problem with this criticism is that our belief that abortion is wrong is not, at its core, a religious belief. Any person with a clear-thinking mind can know that abortion is an evil action and should not be allowed (or promoted) in human society. It goes against the common good of society by devaluing human life and disrespecting the order of human nature, which has the impulse to grow, thrive, and pass life on to the next generation.
Natural Law should be the basis for the civil laws which govern human society. Otherwise, what would laws be based on? Without an understanding of the natural law, people who happen to be in power can impose their arbitrary will with no reference to anything higher than themselves. The Catechism again says, “The natural law, the Creator’s very good work, provides the solid foundation on which man can build the structure of moral rules to guide his choices. It also provides the indispensable moral foundation for building the human community. Finally, it provides the necessary basis for the civil law with which it is connected, whether by a reflection that draws conclusions from its principles, or by additions of a positive and juridical nature” (CCC 1959).
The natural law is written on our hearts and guides the human race to goodness and happiness. This is not a specifically Christian teaching, but one that even pagans such as Cicero have recognized as a sure moral guide and pathway to flourishing in society.