Then the Lord said, “Because the outcry against Sodom and Gomorrah is great and their sin is very grave, I will go down to see whether they have done altogether according to the outcry which has come to me; and if not, I will know.” – Genesis 18:20-21 (RSVC)
Introduction: Principles and Consistency
One of the defining moments in my Catholic education was the realization that Church teaching on sexual ethics formed a sort of “seamless garment”, unified by an internal logic that accounts for every sexual prohibition – from contraception, to masturbation, to homosexuality – in a fairly intuitive manner. For when analyzing sexual activity itself from a Catholic “natural law” perspective, if the procreative dimension can be eliminated as optional and a barrier can legitimately be placed between the man and the woman, then the body of each person is related to the other as little better than any other physical body. At that point, it hardly seems to make a significant difference if the man derives sexual pleasure from a woman, or his own hand, or an inanimate object, or even the bodies of multiple other people. Provided that all persons involved freely consent, the objective difference between any two non-procreative actions becomes so thin as to render them nearly morally equivalent. Sever the link to procreation at the start, and all of the philosophical “natural law” objections to traditionally forbidden sexual activities slowly (but inevitably, and logically) collapse, with nothing but personal preference and consent to hold it back.
Thus, I came to value the Catholic approach to sexual ethics as something built on an airtight logic, according to which it would be impossible for the Church to abandon its condemnation of contraception or homosexual activity without (inevitably, and logically) surrendering everything it has always taught about the necessary procreative dimension of sexual activity. As an ethic that is not the least bit arbitrary in its details, but rather is seamlessly tied together through and through, we can see that the whole thing must stand or fall together. Reject the argument that sexual activity has any fundamental or indispensable and natural link to procreation – as our culture has done at least since the sexual revolution – and the inexorable result (apart from appeals to Scripture) is a radical new path toward embracing the conclusion that everything can be permitted. The only remaining moral condition is that there must be genuine consent from all involved, such that no individual is harmed, exploited, or otherwise violated against their will. This much, at least, is still observed by our culture as an intuitive moral principle.
To the traditionally minded Catholic, however, an awkward tension quickly presents itself. On the one hand, the moral difference between homosexual and contraceptive and masturbatory actions seems to be very thin: for all such actions are considered illicit, intrinsically and gravely disordered, on account of the same fundamental rationale. And yet, homosexual actions are frequently identified as something far worse than the others: for the sin of Sodom and Gomorrah is one of only four sins described in Scripture as “crying out to heaven for vengeance”. In this essay I will explore the foundation of that tension, and attempt to articulate an interpretive lens that can offer a principled resolution.
It is perhaps somewhat shocking to observe that our modern moral instinct regarding consent has not always been historically common. Prior to the advent of Christianity, Greco-Roman culture was in fact disturbingly accustomed to the sexual exploitation of both men and women. In Chapter 3 of her book Paul Among The People, Sarah Ruden explains how “[a] telling slave profession was that of the deliciae (“pet”) or concubinus (“bedmate”), a slave boy whose main duty was passive anal sex with the master” (p. 55). The distinctly passive nature of this sexual activity was important, Ruden pointed out, because Greco-Roman culture held there to be a critical difference: “the active partner in homosexual intercourse used, humiliated, and physically and morally damaged the passive one” (p. 49), but without at the same time incurring any harm to himself: for “when it came to active homosexuals: these were thought only to draw their passive partners’ moral and physical integrity into themselves” (p. 67). “Penetration, after all, signaled moral uprightness… courage, honesty, and responsibility were strongly linked to physical virility in the Greek and Roman minds” (p. 53). And indeed, to a certain extent the Greeks and Romans “even held homosexual rape to be divinely sanctioned”, particularly when inflicted as a punishment: “There was an idol of sexual aggression, Priapus, the scarecrow with a huge phallus who was said to rape intruders, lawfully policing gardens through sexual threat, pain, and humiliation” (p. 54).
To be sure, anal penetration of women also “did happen often, but men valued it less than penetration of boys; women were made to be penetrated anyway; a real man needed to transform an at least potentially active and powerful creature into a weak and inferior one” (p. 54). And once incurred, the stigma was essentially overwhelming and permanent: “The only satisfying use of an adult passive homosexual was alleged to be oral or anal rape – the satisfaction needed to be violent, not erotic. Greek and Roman men, in public, would threaten bitter male enemies with rape” (p. 51). In one fascinating story, the historian Livy recounts the (foiled) conspiracy of an orphaned youth’s stepfather, who tried “to have him ‘destroyed’ by anal rape in the course of initiation into the cult [of Bacchus]: the stepfather wanted to snatch up the forfeited inheritance” (p. 64). Thus the Roman poet “Juvenal depicted the doom of any actual passive homosexual’s reputation as certain”, meanwhile the active partner “had no comeback from his callous and selfish behavior. There were no derogatory names for him. Except for some restraint to avoid conflict within his actual household, he positively strutted between his wife, his girlfriends, female slaves and prostitutes, and males” (p. 53). The poet Catullus even celebrates a certain bridegroom who has “the ‘proper’ attitude” toward his pet slave boy, which amounts to nothing less than “use the kid and throw him aside when convenient. Once you have polluted him, you can catch the same pollution by getting close emotionally. This is how twisted and doubled back the ethics of homosexuality were among the Greeks and Romans. This is what Paul and his readers were seeing.” (p. 58)
Crying Out For Vengeance
Armed with an awareness of this historical context, we are perhaps better equipped to reflect upon the traditional list of “sins that cry out to heaven to vengeance” in Scripture. These are listed in paragraph 1867 of the Catechism of the Catholic Church, and include: the blood of Abel, or murder (Genesis 4:10); the sin of the Sodomites (Genesis 18:20; 19:13); the oppression of slaves and foreigners, and the exploitation of widow and orphans (Exodus 3:7-10; 22:20-22); and the defrauding of wage earners, or cheating the laborer of his due (Deuteronomy 24:14-15; James 5:4). Surveying this list with a critical eye, one might begin to wonder: Why does Scripture call out these specific sins as demanding vengeance from heaven, as opposed to so many other grave sins that do not? Is this essentially an arbitrary list, something that we should just receive obediently from Scripture without questioning? Or is there some sort of internal logic, a deeper unifying principle or element that all of these sins share in common? To be sure, it seems obvious why the murder of an innocent would demand vengeance from heaven. Similarly with slavery and oppression, and the exploitation of vulnerable persons. Even the defrauding of workers fits easily into the same pattern, for it inflicts terrible suffering upon workers and their families by exploiting their labor and forcing them into poverty. But why is “the sin of the Sodomites” included?
The sin of Sodom, of course, is frequently referred to as simply “sodomy”. And yet the precise meaning of “sodomy” is not always quite clear. An entire dissertation could likely be written on the history of this term in both Catholic theology and civil law, which at various times and depending on the context is taken to refer to:  anal sex specifically; or  both anal sex and oral sex generally, between any two people, even if this occurs between a man and a woman;  specifically homosexual acts, whatever these might be, between two men or two women; or even  any and all sexual activity whatsoever that is “unnatural” or contrary to nature, up to and including masturbation, contraception, and bestiality. (Among Catholics today, it is generally the third definition that is intended, although the second definition survives and will typically be conceded if pressed for clarity.) In any case, regardless of how the term is defined, the common explanation – if any can be found – for why the sin of sodomy “cries out to heaven” boils down to absolutely nothing more than the fact that it is considered a sin against nature.
But to the discerning mind, this explanation is neither satisfying nor intellectually coherent. To be sure, it makes for a flashy talking point – “Homosexual activity is contrary to nature, and cries out to heaven for vengeance!” – but in fact, it creates more confusion and raises far more questions than it answers. Perhaps we should pause here for a moment to recall that “vengeance” is, by definition, nothing other than a remedy to a grave injustice. Now consider again the innocent murder victim, the oppressed slave or foreigner, the exploited laborer: these are manifestly (even intuitively!) grave injustices, which cry out to heaven for vengeance – which is precisely justice. And yet, however much we might agree that homosexual acts are “contrary to nature” (in the Aristotelian-Thomistic sense of the term), this fact offers absolutely nothing to explain why homosexual acts should be singled out for special attention; on the contrary, by this logic it ought to follow that every sin against nature cries out to heaven for vengeance, not merely homosexuality. Nor does this rationale offer any explanation to the deeper question of why any sin against nature should be linked so strongly to a question of grave injustice in the first place.
Something about this analytical framework is deeply wrong. In order to sustain the claim that homosexual acts cry out to heaven because they are contrary to nature, we must logically hold that all sins traditionally understood as being contrary to nature (including contraception and masturbation) demand vengeance from heaven for precisely the same reason, and are morally tantamount to slavery and murder in the eyes of heaven. But this claim is never made. Or perhaps, we should admit that this is too much, and simply defend the narrower claim that homosexual acts specifically (and only homosexual acts) cry out to heaven, because Scripture makes this much clear. But then we find ourselves without any coherent answer to the question: Why should this specific sin cry out to heaven? How does it have any sort of connection to justice? We could deny that this list of sins has any common principle, but then we risk dismissing Scripture’s condemnation as fundamentally arbitrary and inexplicable. Is that finally the answer, a dead end with no rational account? Or could the sin of Sodom share a core similarity with all of the other sins on this list, something so radically unjust as to demand vengeance from heaven?
Justice: The Interpretive Key
If it is not already obvious, an answer quickly becomes evident if we simply recall the twisted “ethics” of homosexuality that existed in ancient Greco-Roman culture. For here we see – clearly, vividly, unmistakably – a cultural practice of sodomy which used and exploited vulnerable human persons through the combined endorsement of “active” homosexuality and social stigma of “passive” homosexuality. And it is in contrast with this practice that Paul advances a radically new, Christian claim, according to which “he makes no distinction between active and passive: the whole transaction is wrong… Paul places on a par all the male participants in homosexual acts… clearly implying that they are all morally degraded and that they all become physically debilitated from the sex act with each other. Such effects were unheard of among the Greeks and Romans” (Ruden, pp. 66-67).
Even more to the point, Sarah Ruden highlights the deeper meaning of the language that Saint Paul uses in Romans 1:18 “to lead into his blasting of homosexuality: ‘For the wrath of God is revealed from heaven against all ungodliness and wickedness of those who by their wickedness suppress the truth.’ Wickedness sounds either comically old-fashioned or fairly vague to modern readers. But people of Paul’s time who were fluent in Greek, if they could time-travel and learn English, would translate the word as ‘injustice’. There is nothing vague about it. It is about hurting people. Paul pairs the word with ‘ungodliness’… but he repeats ‘wickedness’. Hurting people really shows how much contempt you have for God. In the Greco-Roman as well as the Jewish tradition, outrageous cruelty or exploitation insulted divinity, which was roused to avenge the helpless” (p. 69). “Paul’s Roman audience… would have been surprised to hear that justice applied to homosexuality, of all things. But many of them – slaves, freedmen, the poor, the young – would have understood in the next instant. Christ, the only son of God, gave his body to save mankind. What greater contrast could there be to the tradition of using a weaker body for selfish pleasure or a power trip?” (p. 71) It is precisely sodomy of this sort – viewed under the lens of sexual exploitation, and indeed even sexual violence – that would fit harmoniously into the traditional list of sins that cry out to heaven: not merely as a sin against nature, but as a sin against nature and against justice. And just as with murder, just as with slavery and oppression, just as with the exploited worker, here we can see a victim on whose behalf vengeance is demanded from heaven. The element of injustice in this sin is not only obvious, and even intuitive, but explicitly highlighted by Saint Paul.
Sodom In Scripture
Turning to reflect on “the sin of Sodom” in Scripture, we should be attentive to a preliminary distinction: the “sin of Sodom” is clearly something broader than our derivative (and typically much more modern) concepts of “sodomy” or “homosexuality”. This is not to suggest that the sin of Sodom no longer exists today, much less to suggest that it has no link to our modern terminology. But it does highlight the logical fallacy of presuming that the “sin of Sodom” is easily understood by the modern reader, especially through reference to those derivative concepts. That being the case, if our interpretive lens of injustice is correct, it follows that we should be able to turn to Scripture and observe that the biblical “sin of Sodom” was marked by some sort of grave injustice, in much the same way (even if not precisely the same way) that an element of injustice was evident in Greco-Roman culture. And this is precisely what we do find in Genesis 19, where the men of Sodom demand that Lot surrender his guests for them to rape. As Jimmy Akin explains, the tradition is that “Sodom was a city known for attempting to committing homosexual rape on travelers, an act which immediately preceded its destruction”. For this reason alone, there is an obvious link to injustice bound up with the biblical sin of Sodom. And yet “the sin of Sodom” is also more than this, for we read in Ezekiel 16:49-50 (RSVC): “Behold, this was the guilt of your sister Sodom: she and her daughters had pride, surfeit of food, and prosperous ease, but did not aid the poor and needy. They were haughty, and did abominable things before me; therefore I removed them, when I saw it.”
Make no mistake, the “abomination” of homosexual activity (and homosexual rape in particular) stands at the capstone of this list of offenses presented by Ezekiel. But at the same time, it is evident that “the sin of Sodom” is broader than unqualified homosexual activity, and is not unrelated to injustice against the poor and needy. Here it is helpful to recall Sarah Ruden’s observation that in the Jewish tradition “outrageous cruelty or exploitation insulted divinity, which was roused to avenge the helpless.” Viewed in that light, it is obvious why homosexual rape (even if this was not the only sin of Sodom) would appropriately be taken to summarize, encapsulate, and effectively define the legacy of the whole city for all time. For it was through this specific and horrific act of sexual violence that the guilt of every last man in Sodom (save one) was made unmistakably manifest: attempting to carry out an action that simultaneously and gravely offended against both nature and divinity, and for that reason cried out to heaven for nothing less than the vengeance that was achieved through the destruction of the entire city.
If we value intellectual consistency, it makes little sense to hold that the homosexuality of the men of Sodom cried out to heaven merely on account of being a sin against nature. To be sure, there is no doubt in the Catholic tradition regarding the condemnation of all homosexual activity as being contrary to nature: but that element alone cannot be why a sin demands vengeance from heaven. Instead, it is the element of injustice (even violent injustice) that cries out, on behalf of a victim who is harmed or otherwise exploited. Just as Abel’s blood cries out from the ground on his behalf, just as the cries of slaves and oppressed women and exploited workers naturally reaches out to heaven, so too with the victims of sodomitical violence.
And indeed, this interpretation accords with the traditional classification of sins in Catholic theology. Here one might recall Dante, who places sins of lust in the first circle of the Inferno, while sins of violence are located much deeper, in the seventh circle. Better yet, we might consider Thomas Aquinas, who holds that sexual sins against nature (the “unnatural vices”) are among the greatest sins considered according to lust, and yet at the same time affirms that “justice is a greater virtue than chastity, so injustice is a greater evil than unchastity, and thus all things considered, Aquinas would consider rape a greater evil than masturbation or contraception”. Again: “This is all quite easily confirmed when we look at the grounds for ranking the second class of sins of lust, the ones proceeding on natural principles: simple fornication is the least because it involves no injustice, adultery is worse because it is also an act of injustice, rape is worse because it is not just an act of lust and injustice but is also violent… [and] injustice is recognized elsewhere as (considered properly in itself) a worse vice than lust.”
It is specifically the added element of injustice that magnifies the gravity of a sin against nature. This is the interpretive lens that is consistent with Saint Paul, with Genesis and Ezekiel, and with the Catholic tradition. And it is most consistent with common sense: for when we consider consensual sins of lust that lack any element of violence or injustice being inflicted on a victim, it seems absurd to classify those sins (even if they are against nature) as even remotely equal to murder or slavery. On the contrary, it is victims of systemic sexual abuse who have an obvious and indisputable basis upon which to cry out to heaven for vengeance. If we wish to effectively evangelize our modern culture, we would do well to continue reflecting on these important distinctions.
 For further reading on this subject, consider Elizabeth Anscombe: http://www.orthodoxytoday.org/articles/AnscombeChastity.php
 cf. this explanation by Jeff Mirus, which simultaneously identifies the sin of Sodom with homosexuality specifically, and explains its inclusion on the list as due to being a sin against nature: https://www.catholicculture.org/commentary/articles.cfm?id=29
 cf. Aquinas, Summa, II.II, Question 108 (on Vengeance) and Question 158 (on Anger)
 cf. Ed Feser: http://edwardfeser.blogspot.com/2012/10/whose-nature-which-law.html “…what is ‘natural’ for us thus means, in classical natural law theory, [that which] tends toward the realization of the ends which, given our nature, define what it is for us to flourish as the kind of things we are. [Similarly] what is ‘unnatural’ thus means something like [that which] tends toward the frustration of the ends which, given our nature, define what it is for us to flourish as the kind of things we are… Thus, when natural law theorists talk about acting in accordance with nature, they do not mean ‘natural as opposed to artificial or man-made.’ For example, when they say that contraception is [contrary to nature] they mean that it positively frustrates the natural ends of the sexual faculties… And methods that do not involve the use of any man-made or artificial devices (such as withdrawal) can frustrate this end just as much as the others can, and therefore are in the relevant sense ‘unnatural.’ … Natural law theorists also do not mean ‘natural’ in the sense of commonly occurring in the ordinary course of nature. All sorts of things commonly occur [that] tend to frustrate our nature — injuries, diseases, floods, earthquakes, and, for that matter, immoral choices… These are not ‘natural’ in the relevant sense of fulfilling our nature even though they are ‘natural’ in [a] different sense…”
 Jimmy Akin: “If you look at passages like Leviticus 18:22 and 20:13, you’ll see that homosexuality is specifically called ‘abomination’ (the same word as in Ezekiel 16:50). So the idea that the Hebrew ethical tradition viewed homosexuality as a-okay but rape as a no-no is simply wrong. They were both abomination, and combining the two was doubly abominable – the kind of thing that could, y’know, get your city destroyed by God or something.” Thus, what Ezekiel shows is that “Sodom was characterized by a bunch of decadent and self-indulgent sins that eventually led it to commit abomination before God, leading him to destroy it – the abomination in question being understood as homosexual rape, in a literary allusion to the Sodom narrative in Genesis where attempted homosexual rape is presented as confirming the iniquity of the city for the angelic messengers and being the final straw that results in its destruction.”
 Summa Theologiae II-II, question 154, article 12, reply to objection 4. In order from least to greatest, the “unnatural vices” include: masturbation (“which consists in the mere omission of copulation with another”), contraception (or any sexual activity between men and women “not observing the right manner of copulation”), homosexual actions (which is a more grave sin against nature because “use of the right sex is not observed”), and finally bestiality (which is “the most grievous [sin against nature] because use of the due species is not observed”).
 Joseph Bolin: http://www.pathsoflove.com/blog/2009/06/aquinas-on-sexual-sins-dangers-of-speaking-formally/ Again: “The teaching of medieval theologians that such sexual sins as masturbation, sodomy, and contraception are more perverse, as sexual sins, than fornication or adultery or even rape […] angers many people today. But this teaching must be understood properly. The medieval theologians are claiming that certain kinds of sexual sins more seriously offend the virtue of chastity than do others. They are not saying that these sins are for this reason less grave as sins than adultery or rape, for instance. After all, adultery and rape are very serious violations of the virtue of justice as well as being violations of the virtue of chastity. Thus, as a sin, rape is far more serious than masturbation or homosexual sodomy because it not only offends chastity but also gravely violates justice.”