Christianity: Roman Catholic

Law and Ethics

Primary Author
Chara Scroope,

Canon Law

Canon law refers to the body of laws that govern the whole Church and the expected behaviours of individual Catholics. The canon law of the Catholic Church is updated to reflect the political, economic, cultural, religious and social changes since the Church’s inception. The current iteration of canon law was proclaimed by Pope John Paul II in 1983. It contains 1,752 ‘canons’, many of which relate to:

  • The rights and duties of the clergy and
  • Organisational structure
  • Teaching and missionary activities
  • Catholic worship practices
  • Ownership and administration of property
  • Administration of justice in church courts 

Ecclesiastical Court

An ecclesiastical court is a tribunal established by religious authorities to address disputes or religious matters. The functions of the ecclesiastical court is largely restricted to religious issues and church property. The tribunals of the Catholic Church are governed by canon law and members of the court are those trained in understanding and implementing canon law.

Guiding Ethical Principles

The Ten Commandments

The Ten Commandments (Exodus 20:1-17; Deuteronomy 5:6-21) are believed to be divine laws that establish the foundation of ethical practice. The Ten Commandments institute ethical rules relating to: respecting God and other authority figures (such as parents); honouring the holy day of rest (Sabbath); and a prohibition on killing other human beings, lying, stealing, sexual misconduct and coveting.

Catechism of the Catholic Church articulates the Church’s official interpretation and position on the moral topics discussed in the Ten Commandments. Many Catholics try to follow the ethical guidelines established in the Ten Commandments and the Church’s interpretation of the commandments. However, individual Catholics may have personal interpretations and applications of moral principles.

Sermon on the Mount

The Sermon on the Mount by Jesus Christ was an address to a large crowd of listeners, instructing them on how to live a life based on love (Matthew 5-7). One of the fundamental principles in Christian ethics is known as the ‘golden rule’, which states “do to others what you would have them do to you” (Matthew 7:12). Many of the most common Catholic sayings and prayers are found in the Sermon on the Mount, such as the Lord’s Prayer.


Sin generally refers to the breach or violation of religious law or ethical norm through omission or commission. In Catholicism, receiving God’s grace is how one is able to atone for their sins. The Sacrament of Reconciliation is one of the main ways an individual may receive God’s grace. There are various categories of sin:

  • Original Sin: Original sin refers to the inherently sinful nature of humanity due to the actions of the two original humans.
  • Actual Sin: Actual sin is the acts, thoughts, words or deeds that are evil and transgress from God’s will. Actual sin is subdivided into different categories on the basis of its gravity as well as on the basis of one’s awareness of the sin. For example, a mortal sin is a grave action that is deliberate and committed in full knowledge of its gravity and the sinner’s will (such as murder). Meanwhile, a venial sin is a smaller matter committed with little to no self-awareness of wrongdoing.

Sexuality, Marriage and Divorce

The Roman Catholic Church understands sexuality as a gift from God that is inherent to every human being. Sexual activity is considered to be an expression of sexuality within the context of marriage (understood as a sacred covenant between a man and a woman). These principles shape the Church’s position towards family, sexuality, marriage and divorce. However, individual practices and perspectives by lay followers may vary from the Church’s official position.



The Roman Catholic Church views sexuality in the context of the sacred unity between a man and woman (i.e. marriage) as well as procreation (Catechism of the Catholic Church: 2360-2379). Accordingly, acts outside of this formula are usually considered to be a sin, such as fornication, pornography, masturbation and homosexual activity. Moreover, refraining from sexual acts outside of marriage (known as chastity) is highly valued.


In terms of sexuality and reproductive practices, the Roman Catholic Church generally does not support the use of artificial contraceptives as a method to prevent birth. There are also sexual ethical guidelines specific to the clergy of the Church. For example, all ordained men are to be celibate (refrain from marriage and sexual acts), with the exception of married deacons, who must be married prior to ordination.



In Roman Catholicism, marriage is understood as the Sacrament of Matrimony. Catholicism views marriage as a sacred covenant between a man and a woman with each other and with God. Those who enter the Sacrament of Matrimony are expected to enter into the union with the intention that it will be permanent (unto death), faithful (without adultery) and fruitful (open to the possibility of children). Generally, the Catholic Church only allows for someone to marry a person who is the opposite gender and has either never married before or is widowed.



The Roman Catholic Church considers the nature of marriage to be a sacred unity that is indissoluble. The Church makes a distinction between a divorce (as an act of civil law) and an annulment (an act of canon law). An annulment confirms that, as a sacrament, the marriage was invalid. For example, if one or both spouses did not intend to enter a permanent, faithful and fruitful union. An annulment is separate from a civil and divorce that the couple might pursue. Unless someone receives an annulment, they will be unable to remarry in the Church.

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