The Ten Commandments, also called ‘the Decalogue’ (ten words), are the most famous passage in the Bible. Presented in the Hebrew Bible as having been revealed directly to the Jews by God, they were subsequently assimilated into Christianity and they have occupied a central place in Christian, and popular, moral thinking for centuries. There are two versions of the Decalogue in the Old Testament: one in Exodus chapter 20, which is the older version, presented in the context of the early history of Israel; and the other in Deuteronomy chapter 5, a later, prophetic version, presented as a historical reminiscence in Moses’ dying speech.
Readers of the Ten Commandments today can be confused if they do not realise that the two versions of the Decalogue are numbered in different ways. It is easiest to understand the difference by starting at the end. The Greek tradition, Calvin and the Reformed and Anglican traditions follow the text of the older, Exodus version (Ex 20:2-17), which ends with a single commandment (verse 17) forbidding the coveting of one’s neighbour’s property, including his wife, and which contrives to keep a total of ten by dividing the opening commandment forbidding strange gods into two, making the forbidding of idols the second commandment. By contrast, St Augustine and, following him, the Catholic and Lutheran traditions follow the later, Deuteronomic version (Dt 5:6-21), which closes with two distinct commandments forbidding ‘coveting’: the first of one’s neighbour’s wife, and the next of one’s neighbour’s property. This version opens with a single commandment which forbids strange gods as well as idols (of God). This differing numeration explains why Roman Catholics today refer matters of sexual morality to the sixth commandment, while Anglicans ascribe anything to do with this particular prohibition to the seventh commandment. Incidentally, this beginning to recognise the dignity of the Israelite woman, even in so primitive a way as by separating her from her husband’s property and giving her a distinct commandment, is an indication of the historical development between the Exodus and Deuteronomic versions of the Decalogue.
The contents of the Decalogue fall into two groups of fundamental moral commands and duties imposed by God: an early, brief group devoted to giving absolute respect to God, to the divine name, and to the Sabbath, the Lord’s day; and a second, larger group which focuses on respecting one’s fellow-Israelites, beginning with one’s elderly parents, and prohibiting murder, adultery, kidnapping (later generalised to stealing), calumniating, and coveting and stealing another man’s wife and his property (the former being included as part of the latter in Exodus). The individual commands were expanded and applied to changing situations in the course of liturgical use at festivals and through prophetic preaching.  Today, the precepts of the Decalogue can be viewed less historically and more abstractly, as protecting basic human values: the values of religion, life, marriage, freedom, reputation and property. Initially, they had nothing to do with human rights – which are a much later philosophical development – but they can form a basis for arguing to a theory of human rights.
Initially the Decalogue got its moral authority not from any intrinsic ethical force, but from the will of God as divine law, with God acting as the major party in a ‘covenant’, or treaty, which he undertook freely with his newly-formed people of Israel as they escaped from Egypt. On their part, in a solemn sworn agreement, the new people of Israel undertook, in return for God’s choice and continuing protection, to obey ‘the words of the covenant, the ten commandments’ (Ex 34:28). An attractive interpretation sees this agreement as modelled on ancient political treaties between sovereign kings and their vassal countries: a historical preamble and list of past favours (‘I am the Lord your God, who brought you out of the land of Egypt . . .’ [Ex 20:2]); a list of the basic stipulations (the Ten Commandments); and concluding with blessings and curses for observance or disobedience (Deut 11), with the document to be kept safe in a national sanctuary (the ark of the covenant, Ex 25:16). The whole is summed up well in Ex 19:3-6:
Then Moses went up to God; Yahweh called to him from the mountain, saying, ‘Thus shall you say to the house of Jacob, and tell the Israelites: You have seen what I did to the Egyptians, and how I bore you on eagle’s wings and brought you to myself. Now, therefore, if you obey my voice and keep my covenant, you shall be my treasured possession out of all the peoples. Indeed, the whole earth is mine, but you shall be for me a priestly kingdom and a holy nation.’
Jesus and the Decalogue
As a devout Jew, Jesus was familiar with the Hebrew Bible and among the early Christians there was profound interest in how his teaching related to the traditional teaching in Israel, which his enemies had accused him of flouting. This interest came especially from Jewish Christians, whose concerns and needs were of major significance to the author of Matthew’s Gospel. As I showed in an earlier article on the Sermon on the Mount, far from dispensing with the Ten Commandments of Israel, Jesus insisted on their continuing relevance and their fulfilment, and he even took pains to show their deeper significance and application for his followers (Mt 5:17-48). Moreover, all of the synoptic gospels make a point of recording the conversation between Jesus and the rich young man who wanted to know how to gain eternal life, when Jesus said, simply, ‘keep the commandments’ (Mk10:17-22; Mt 19:16-30; Lk 18:18-30). According to Mark, Jesus instanced those forbidding murder, adultery, theft, false witness, defrauding, and the command enjoining care for one’s parents; but he added that one thing the young man was lacking was to ‘follow’ Jesus. Luke’s later version is basically faithful to Mark’s, but Matthew’s version includes as a commandment, less than accurately, the injunction to ‘love your neighbour as yourself’, and adds, perhaps influenced by the earlier Sermon on the Mount (Mt 5:48), that if the young man wished to be ‘perfect’ he should ‘follow’ Jesus (Mt 19:19-21).
The Ten Commandments inform the teaching of Jesus in another conversation between him and a Jewish lawyer which is recorded by Mark and Matthew. Given the absolute authority of all the Ten Commandments, and the multiplication of many other minor laws and rules in Israelite observance, a question had arisen among the Jews and was now put to Jesus: was there any priority among them, and if so, which commandment was ‘the first of all’, as Mark phrases it (12:28), or ‘the greatest’, according to Matthew (22:34)? In his reply Jesus had no doubt: moving outside the Ten Commandments, he replied that ‘the greatest and first commandment’ was to love God totally (Mk 12:30; Mt 22:37-38; see Deut 6:5). And then, according to Mark, he added for good measure, as was usual with him, ‘The second is this, “You shall love your neighbour as yourself”’ (Mk 12:31), which Matthew records as, ‘A second is like it: “You shall love your neighbour as yourself”’ (Mt 22:39).
This Jewish question about a priority among the commandments in the Mosaic Law is characteristically omitted by Luke, who was writing more for Roman gentiles. Yet it is interesting to note that he finds Jesus’s answer valuable enough to use it in his record of a conversation between Jesus and a lawyer (Lk 10:25-28) who asked him, ‘what must I do to inherit eternal life?’ This question strangely duplicates that of the young man later in Luke that we looked at above (Lk 18:18-30), when Jesus replies by instancing the commandments and then advising him to become a disciple; yet the reply this time is significantly different. Jesus asks the lawyer what he himself thinks from his knowledge of the Mosaic law, and it is the lawyer who quotes the obligation to love God above all and to love one’s neighbour as oneself (Lk 10:25-27) as the way to eternal life, which Jesus applauds. Luke, alone among the evangelists, then introduces the famous parable of the Good Samaritan as Jesus’s memorable reply to the lawyer’s next question: ‘But who is my neighbour?’ (Lk 10:28-37).
Is love the answer or the question?
This command to love one’s neighbour as oneself is to be found in the Old Testament in Leviticus 19:18, and, as we have seen, Jesus quotes it along with the command in Deuteronomy 6:5 to love God totally in response to the lawyer asking him which is the greatest commandment in the Law. Viviano comments that ‘the combination of these two commands is not clearly attested before Jesus and marks an important moral advance’. Loving God leads to loving one’s neighbour also as God’s beloved. Moreover, Jesus observed that ‘on these two commandments hang all the law and the prophets’ (Mt 22:40), a statement which is original to Matthew’s Gospel. For Matthew’s Jewish-Christian readers, this combined ‘Great Commandment’ was a summation of the entire Mosaic Law. It also provided the later traditional headings for the two sub-groups of the Ten Commandments, love of God heading the first group and love of neighbour the second.
The double Great Commandment does, however, raise at least two questions: what does ‘as yourself’ mean? And does the commandment to love replace the Ten Commandments? The command to love one’s neighbour as oneself has regularly been taken to mean that we should love our neighbour no less than in the way and measure we love ourselves – with the rather tortuous conclusion for some people that we are therefore indirectly justified by the Bible in actually loving ourselves. Alternatively, and preferably, we should regard the command to love our neighbour as ourselves as identifying our neighbour with ourselves, as being part of us, as a fellow-Israelite in the original version in Leviticus.
The necessity of loving one’s neighbour is recognised elsewhere in the New Testament, especially in the letters of Paul, where a connection is established between the command of neighbour-love and the Ten Commandments which throws light on both.In a highly significant passage, Paul writes to the Romans (13:8-10):
Owe no one anything, except to love one another; for the one who loves another has fulfilled the law. The commandments, ‘You shall not commit adultery; You shall not murder; You shall not steal; You shall not covet’; and any other commandment, are summed up in this word, ‘Love your neighbour as yourself’. Love does no wrong to a neighbour; therefore, love is the fulfilling of the law.
In his letter to the Galatians (5:13-14), Paul observed similarly, ‘through love become slaves to one another. For the whole law is summed up [literally, ‘fulfilled’] in a single commandment, “You shall love your neighbour as yourself”’.
In other words, the commandment to love one’s neighbour does not replace the Ten Commandments. It sums them up, observes them and explains their purpose: they are ways of expressing love for one’s neighbour. The once-fashionable but now outmoded ‘situation ethics’ of Joseph Fletcher, which reduced all morality to doing the ‘loving thing’, suffered from an inability to identify just what is the loving thing to be done in various situations. What Paul is implying here is that if one examines how best to love one’s neighbours, one comes up with the requirement not to harm them, but to respect their life, their freedom, their reputation, their marriage and their property; in other words, as Jesus said to the young man, ‘keep the commandments’. As Thomas Aquinas was much later to establish, to love someone is to will what is good for them. Or as James 2: 8 expressed it, ‘You do well if you really fulfill the royal law according to the scripture, “You shall love your neighbour as yourself.”’
The moral teaching of Jesus did not end with his identifying the Great Commandment as the one on which depended ‘all the law and the prophets’ (Mt 22:40). In John’s Gospel he appears to go further, by giving his disciples a ‘new’ commandment. Why did he do so, and what did he mean by it? That will be the subject of a subsequent article.
Jack Mahoney SJ is Emeritus Professor of Moral and Social Theology in the University of London, and a regular writer for Thinking Faith
 Still a very helpful overall introduction to the Commandments in the Bible is J. J. Stamm & M. E. Andrews, The Ten Commandments in Recent Research (London: SCM, 1967).
 See Ex 20-23; Deut 12-26.
 See J. Mahoney, The Challenge of Human Rights. Origin, Development, and Significance (Oxford: Blackwell, 2007), 3-5.
 B. T. Viviano, The Gospel According to Matthew, New Jerome Biblical Commentary, 42:133.
 J. Fletcher, Situation ethics: the new morality (Philadelphia: Westminster Press, 1966).
 St. Thomas Aquinas, Summa Theologiae, I-II, 26, 4
‘Why a ‘New’ Commandment?’ by Jack Mahoney SJ on Thinking Faith