In John Chapter 13 Jesus taught his disciples “A new command I give you: Love one another. As I have loved you, so you must love one another.  By this everyone will know that you are my disciples, if you love one another.”  The Greek word translated “love” in this passage is agape, which refers to the non-preferential humanitarian love that Jesus showed to people rather than the erotic eros or the friendly philos.  This is why some Christians regard agape-love as the only source of Christian ethics, because it was Jesus’ single new commandment and, of course, Jesus was God. Nevertheless, today few Christians agree with this, given that Roman Catholics follow heteronomous ethics and most Protestants a broader Divine Command ethic based on the whole Bible.  It follows that agape is not sufficient as the only source of Christian ethics.

Firstly, while John 13 does state that agape-love is the one commandment by which Christians will be known as Jesus’ disciples, Jesus said this in context.  In Jeremiah 31:33 God promised that “This is the covenant I will make with the people of Israel after that time,” declares the LORD. “I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people.” This suggests that Jesus was referring to the new covenant when he gave the commandment of agape-love, and meaning that Christians would follow all God’s law automatically in both letter and spirit, rather than that they would abandon the rest of the commandments and do whatever they felt was loving instead.  This interpretation is consistent with Matthew 5:18 “For truly I tell you, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished…” and with the rest of Jesus ethical teaching, which is more demanding than the Law of Moses and not less.  For example, in Matthew 5 teaches that Jesus equated anger with murder and lustful looks with adultery.  While Jesus was demanding that Christians should act with agape – treating others as they would wish to be treated and not only following the letter of the law – there is no sense that agape is an alternative source of ethics to the rest of God’s commandments.   The point is that a person acting with agape would neither be angry with somebody nor murder them, neither look lustfully at a woman nor commit adultery with her.  In this way it would be wrong to say that agape is sufficient as the only source of Christian Ethics.

Secondly, for Roman Catholics seeing agape-love as a sufficient basis for Christian Ethics ignores the importance of a well-formed conscience as well as of Scripture, Tradition and Reason (Natural Law) in shaping Christian teaching. Following St Thomas Aquinas’ reasoning, the Catechism affirms that the primary source of Christian ethics is the conscience.  When we face a difficult choice, it is a moral duty to follow conscience.  Our conscientia is that part of our practical reason that applies the general principles of Christian Ethics that we know through synderesis (principles which are consistent with Scripture, Tradition and Natural Law) to the specific situation at hand.  Nevertheless, because consciences can err, leading us to pursue apparent and not real goods, and because synderesis is a habit that needs to be developed, we must take care that consciences are properly formed through a Catholic education.  Church teachings, which underpin Catholic education, provide a short-cut to the decisions that a well-formed conscience would make and when the conscience diverges from Catholic teachings it is a good indication that the conscience is erring.  Pope Pius XII rejected situation ethics in 1952, even before its more agapeistic versions were developed by Joseph Fletcher and JAT Robinson, because while it is consistent with the Roman Catholic understanding of Christian ethics in encouraging Christians to act in conscience, because it ignores the need to form consciences or ensure that their decisions are consistent with Scripture, Tradition and Reason, it leaves individuals vulnerable and without proper moral guidance when they face difficult situations. Fletcher’s claim that there should be no absolutes in Christian ethics, no always and no nevers, conflicts with the Bible’s long list of prescriptive commandments and suggests that agape is instead of the law rather than a fulfilment of it, as Jesus taught.  It is also difficult to define agape-love.  For example, Immanuel Kant argued that human beings are “pathologically loving” and that an action motivated by this love always treat human beings as ends in themselves and never as mere means.  By contrast, Fletcher defends what he calls the agapeic calculus, the greatest amount of neighbour-welfare for the largest number of neighbours possible, making agapeistic ethics seem much like utilitarianism.  While by Kant’s definition, agape could never justify involuntary abortion, suicide or adultery… but Fletcher freely discusses situations in which these would, he implies, be the most loving course of action. Because of this central confusion, it is difficult for people not to confuse a genuinely agapeistic motivation with a more preferential or even selfish motivation. All this shows that it is wrong to say that agape is sufficient as the only source of Christian Ethics.

On the other hand, it is true that Jesus sometimes seemed to break the laws of Moses situationally, for the benefit of people. According to Mark’s Gospel, He healed on the Sabbath and allowed his disciples to pluck ears of corn on the Sabbath, neither of which in life-threatening situations. It seems that Jesus was maximising peoples’ welfare and putting this ahead of obedience to the law, as Fletcher suggested.  Nevertheless, the laws concerning the Sabbath were, Jesus reasoned, there to serve man and therefore could and should be broken when they harm peoples’ welfare.  The same might not be true of other laws, such as the prohibition on murder in Exodus 20:13.  In Genesis 4 God says that Abel’s blood cries out to him from the ground and in Genesis 9 God demands an accounting for any human blood that is shed.  This might suggest that the law against murder is not only to serve humans, but also to serve God because God has an interest in human blood.  As St Paul confirms in 1 Corinthians 6:19-20 “Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price. Therefore honour God with your bodies.” Which implies that human life is sacred and owned by God, so murder offends against God and not only human beings.  If this is true, then it would be impossible to act out of agape-love and kill a human being, even in situations as extreme as outlined by Fletcher, because agape puts love of God first and ahead of love of neighbour, according to Mark 12:28-32. Kant would be right that agape always treats humanity as an end and never as a means to an end, even of maximising human welfare. This suggests that agape-love is not sufficient as a source of Christian ethics, unless one specifies that it includes love of God as well as and ahead of love of neighbour, which would bring following all of God’s commandments into the scope of agape, rather than accepting God’s laws only selectively. This interpretation would be consistent with a more mainstream Protestant Ethic, which aims to follow all those Divine Commands in spirit at least. 

In conclusion, it is wrong to say that agape is sufficient as the only source of Christian Ethic unless one is very specific in defining agape, stipulating that it includes love of God as well as and ahead of love of neighbour, so leads to a broader biblical ethic which always upholds the sanctity of human life.  Certainly, it is wrong to say that situation ethics is the only or even an acceptable Christian Ethic.