Christian Teaching on Sexual Morality

by Richard Swinburne

This essay is part of a series stemming from the ongoing research project “Contemporary Eastern Orthodox Identity and the Challenges of Pluralism and Sexual Diversity in a Secular Age,” which is a joint venture by scholars from Fordham University’s Orthodox Christian Studies Center and the University of Exeter, funded by the British Council, Friends of the British Council, and the Henry Luce Foundation as part of the British Council’s “Bridging Voices” programme. In August 2019, 55 scholars gathered for an international conference at St Stephen’s House, Oxford. These essays are summaries of presentations given in preparation for the conference and during it. They together reflect the genuine diversity of opinion that was represented at the conference and testify to the need for further reflection and dialogue on these complex and controversial topics.

Moral principles are principles about which actions are morally good or bad, and which among good actions are morally obligatory and which among bad actions are obligatory not to do (=wrong).  A moral obligation is an obligation to someone else, and we wrong that someone if we fail to perform the obligation. To wrong God is to sin. There is a longstanding controversy among Christian philosophers as to whether the fundamental moral principles are necessary truths about the moral natures of different kinds of action, or whether they are made true by the will of God. I recommend the former view, which was the view of, among others, Thomas Aquinas and Duns Scotus; it’s simply part of the nature of helping those in trouble that it’s a good action, and simply part of the nature of torture that it is wrong to torture someone. God just sees that these things are so and from time to time tells us this. Actions which are good in all possible circumstances are intrinsically good, and actions which are obligatory in all possible circumstances are intrinsically obligatory. It is intrinsically obligatory to keep our just promises (that is, promises which we had the right to make), and it follows that adultery and divorce without the consent of the other spouse are intrinsically wrong.

I now suggest that if we are given a gift by some benefactor on the condition that we use it for a certain purpose or do not use it at all (that is, he commands us not to use it for any other purpose), it is intrinsically obligatory not to use it for any other purpose. God is our creator; and everything we are and have is a gift from God, except those few gifts given to us by others, principally our parents, whose ability to give their gifts is itself a gift from God. Hence it is a derived moral principle that it is wrong to use any God’s gifts for a purpose other than the one for which God gave it. Our sexual organs are a gift from God. Hence it would be sinful to use them in a way forbidden by him. For 1,900 years, the Christian Church taught with virtual unanimity, as central moral doctrines, that contraception within marriage, remarriage after divorce (with possible exceptions), sexual intercourse outside marriage, and homosexual acts, are sinful. Given that the Church founded by Jesus has authority to tell us which acts God has forbidden, it would seem to follow that all these actions are sinful.

However, we must bear in mind one of Augustine’s rules for interpreting Scripture: “To recognize that some commands are given to all in common, others to particular classes of persons.” Our grounds for supposing a command to have application only to particular classes must surely include the ground that the only reason that we can see for God to issue some command arises from the particular circumstances of that class. In the case where the class concerned is people living in earlier days, it needs to be shown that the circumstances in which God would have reason to issue the command no longer hold. For a thousand years, Christians believed that God had forbidden usury, that is lending money on interest. God had good reason to issue this command at a time when most lending was by rich people to poor people to enable them to feed their families; it would have been cruel to demand not merely repayment of the loan but additional interest as well. But since the development of sophisticated financial arrangements since the 14th century, much lending has been by people of limited means to richer people to enable them to develop enterprises which would make them even richer. In such circumstances, those of limited means are surely entitled to payment for making their money available to the rich. Hence Christian tradition naturally came to see much lending on interest as no longer sinful, and thereby—in my view, correctly—interpreted the prohibition on usury as having a limited application.

Augustine’s rule has in my view important application to the issue of contraception within marriage. The only good reason which I can see for God forbidding this is that—as Genesis 1 reports God saying to Adam and Eve—he wanted humans to “be fruitful, and multiply, and fill the earth.” It is plausible to suppose that if contraception had been practiced widely in early centuries (when so many children died before reaching adolescence), the human race would have died out. But humans are now much nearer to “filling the earth.” If contraception were not practiced now, the earth would soon become too crowded to grow enough food to feed all humans. And that, I suggest, is a reason why, as with usury, the circumstances which made the command a good one for God to issue no longer hold; and so it is plausible to suppose that contraception within marriage is no longer wrong.

I cannot myself see any feature in which the modern world differs from the ancient world which would make any difference to the applicability of traditional views on the sexual morality of divorce (possibly outside certain limits), premarital sexual intercourse, and homosexual acts. Maybe some reader can suggest some such feature. But if not, then since the Church for 2,000 years has taught with virtual unanimity that those other acts are wrong, we must conclude that either the Church is not a reliable source of authority on moral matters (not merely for us, but also for the first century Christians who read Paul’s letters), or that the secular world is not a reliable source. But if we do maintain the Church’s traditional teaching, it would be good if we could see some good reason why God would have forbidden acts contrary to that teaching. In what follows, I will suggest one such reason.

I have argued so far that God has the right to tell us how to use our sexual organs, and that—on the assumption that the virtually unanimous teaching of the Church over 2,000 years that God has forbidden remarriage after divorce (with possible exceptions), sexual intercourse outside marriage, and homosexual acts—it would seem to follow that all these actions are sinful. But, although we cannot always expect to see God’s reasons for forbidding what he forbids, it would be good if we could see what reason God might have for forbidding these particular acts.

It is plausible that a loving marriage between a man and a woman, facilitated by them having sexual desires for each other, involving lifelong commitment to each other, producing children who share the genes of both parents as a result of a loving act between them of a kind which they have had and will have with no one else, nurturing and educating those children to have happy and God-directed lives, in which each child will have a parent of their own sex whom they can trust to guide them on sexual and all other behavior is a very good thing; and so that the reason why God gave us sexual organs is to make such a marriage possible. To be unable to enter into such a marriage is a disability. So it is highly probable that God would forbid any actions which in any way make it difficult for humans to enter into such a marriage.

Humans are so made that we have an enormous influence on each other by how we live, not merely or mainly by the arguments we present to each other for how we ought to live, but by our actual conduct. It seems evident that the prevalence of remarriage after divorce (outside certain limits) and extra-marital intercourse in society in general, and especially any such practice among Christians, makes it difficult for couples to have the sort of marriage described. Not merely does the prevalence of such practices make it much harder for those in existing marriages to maintain lifelong fidelity to each other, but it makes those considering marriage think of it as a possibly temporary union and so already to be not properly serious about the commitment that it involves. So God has a good reason to forbid extra-marital intercourse and (with possible exceptions) remarriage after divorce: the good reason that it helps greatly towards, though of course does not guarantee, the success of many marriages of others.

Fairly evidently, homosexual acts of an already married person would be damaging to marriage. But it needs to be shown that the prevalence of homosexual practices among the unmarried is also damaging to marriage. It would not be damaging if every human was totally, permanently, and unchangeably either heterosexual or homosexual in their sexual orientation. But this is not the case. Some humans have orientations of both kinds, some humans seem to be homosexually orientated for a time and then become heterosexually orientated (and vice versa), and there is—to my mind—credible anecdotal evidence that some sexual orientations are changeable by outside intervention. The survey recently published in Science of the genetic influences on the sexual behavior of nearly half a million individuals strongly confirmed the conclusion that their genes  make a difference (together with unidentified non-genetic influences) to whether anyone has ever had sexual relations with someone of the same sex in only 32% of cases (and presumably some of these  were cases of once-off youthful experimentation, having no effect on permanent orientation). And (to quote the report) “all measured common [genetic] variants together…do not allow meaningful prediction of an individual’s sexual preference.” Other biological and social influences on sexual behavior may include epigenetic influences and influences on the developing foetus in the womb, and the kind of nurture provided by parents (in respects not directly related to sexual behavior). But it seems to me probable that the influence of homosexual friends and celebrities, and teaching in state schools and general acceptance by society of the equal worth of traditional and gay marriage, leads many humans to have homosexual sexual relations and thereby to develop homosexual desires which they would not otherwise have. For that would explain many of the changes of behavior and orientation subsequent to childhood. However, in the absence of any large socio-biological study of the extent of different kinds of non-genetic influences on homosexual behavior and desire, that can only be a provisional but plausible hypothesis. But, given that hypothesis, God has good reason to forbid homosexual activity, even by those who have already developed what they reasonably believe to be a total permanent unchangeable homosexual orientation, because of its bad influence on others, leading them not to be able to enter into a traditional marriage.

But isn’t it unfair that—not through their own fault—some people come to acquire an unalterable homosexual orientation? Yet so many of us, either as a result of nature or nurture, have strong desires to do bad acts of different kinds; like St Paul, most of us have our “thorn in the flesh.” And homosexuals are not the only or even the main “victims” (if that is the right word) of the rules of traditional sexual morality. The official rules of the Orthodox Church forbid remarriage of anyone whose previous spouse is still living for any reason other than that spouse’s adultery, or remarriage at all of anyone who has had three marriages. So many people going through a difficult period in their marriage are tempted to infidelity. And many young people with very strong desires to have sexual intercourse are too young to commit themselves to marriage, or unable to find a suitable spouse, or unable to afford to live away from their parents and so start their married life in a way which will best ensure its success. But for Christians to suffer in a way that helps others to flourish is itself a great privilege; and of course, Christ himself did just that. Those who stick by the rules at some cost to themselves are privileged to share in safeguarding the institution of marriage.

Although breaking the rules of sexual morality is always sinful, there are far more serious sins; and I draw no conclusions from what I have written for how the Church should exercise its pastoral care over those of its members who break these rules, quite often because they do not believe that it is wrong to do so. I pray only that Church may show respect, compassion, and understanding for them; and find some kind of space within its ample bounds for all sinners who sincerely seek to discover and follow the way to sanctity.


Richard Swinburne is Emeritus Professor of Philosophy at the University of Oxford.

Public Orthodoxy seeks to promote conversation by providing a forum for diverse perspectives on contemporary issues related to Orthodox Christianity. The positions expressed in this essay are solely the author’s and do not necessarily represent the views of the Fordham-Exeter project leaders, the conference as a whole, or the Orthodox Christian Studies Center.