In Romans 11:16b-24 Paul presents a word picture in which the branches of a cultivated olive tree have been broken off and a wild olive branch has been engrafted into the cultivated root. The resulting image of a whole tree consisting of differentiated parts is particularly useful in the Roman church context where tensions have arisen between Christians of different ethnic identities. But hidden within the metaphor is the repetition of two key phrases (according to nature/contrary to nature) that harken back to the argument put forth by Paul’s rhetorical spokesperson in Romans 1:18-32 and to the response that begins in chapter two. The olive tree metaphor contributes to a larger rhetorical argument in which Paul   an earlier polemic presented in chapter one by describing accepted acts of both human and divine agency that are "contrary to nature."
However, before examining this argument, a short overview of the socio-historical background may prove helpful.
Roman historian Suetonius reports that sometime between 49 and 52 CE Claudius "‘expelled from Rome Jews who were making constant disturbances at the instigation of Chrestus'" (Fitzmyer 77). Since the late 1960’s it has been proposed that conflict broke out between Jews and Jewish Christians in Rome over Christian claims that Jesus was the messiah. After Claudius’ death in 54 CE, his edict lapsed and the expelled Jews began to return home. Jewish Christians found a church that had continued to grow without their influence, setting the stage for interethnic conflict between rival Christian factions with differing religious sensibilities (Fitzmyer 76-77). Paul addresses the olive tree image to these factions, creating a shared identity  for Jew and Gentile (Esler 123). In this way he hopes to diffuse the conflict, acknowledging cultural differences while calling both groups to a joint identity in the blessing of Abraham.
The image of the olive tree, as opposed to the more traditional biblical image of the vine, is of particular value in this context. According to Greek myth, the goddess Athena planted the first olive tree on the site of the Acropolis. Thus Paul’s choice of the olive tree, evoking associations with both Athens and Greek culture, serves as a powerful symbol for Gentile believers who would no doubt be proud of the intellectual achievements of the cultured pagan world (Davies 160).  But something is amiss with Paul’s metaphor. Theophrastus of Eresus (371-287 BCE) describes methods used by the Ancient Greeks to propagate olive trees by engrafting scions from cultivated olive-producing branches into the trunks of wild olive trees. The wild trees have a more extensive root system for gathering nutrients and water from the soil, while the cultivated stock is selected based on its known reputation for producing fruit (Esler 112-114). But Paul’s image is reversed, engrafting a wild olive branch into a cultivated olive tree. While some commentators have asserted that this infusion of wild stock would rejuvenate the cultivated plant (Byrne 346), Philip Esler suggests that a proper understanding of this passage is not concerned with how much Paul understood of ancient olive cultivating techniques. Rather, the inversion Paul describes is a way of undermining the pretensions of Gentiles in the Roman church (Esler 122-123). It is not Greek culture that Paul deems valuable, but the rich heritage of his own people:
This is the root into which the Gentile believers have been grafted. The wild olive produces little or no oil and is nearly profitless (Davies 160). Thus Paul’s meaning is clear: Gentiles who have been joined to the covenant community ought not to think too highly of themselves. Though their first association with the image of the cultivated olive tree would be their own cultural heritage, Paul has cast the Gentiles in the role of the wild branch, sharing in the blessings of the root but not producing any fruit themselves. Without the rich heritage of the Abrahamic line, the Gentiles would be nothing.
What’s more, Jewish Christians hearing Paul’s metaphor are likely to have made some rather disturbing associations or their own. For in engrafting of the wild olive (agrielaios) into the "good" olive (kallielaios), two passages in the Law are immediately brought to mind.  Leviticus 19:23-25 indicates that the fruit of any tree should be considered uncircumcised (or "unclean," akatharsia, in the LXX) for the first three years in which the tree produces. The fourth year’s fruit is set aside as an offering to the Lord; and in the fifth year the Israelites are allowed to partake. Here Paul plays with the concepts of Gentile, unclean, and uncircumcised within his metaphor. And just before this passage, Leviticus 19:9 11 forbids the mixing of crops in a vineyard (the Jewish analog for the olive tree metaphor), the plowing of a field with both an ox and a donkey or the mixing of textiles. The image of mixing wild and cultivated olive trees, especially in conjunction with the idea of the "uncircumcised" branch, would certainly evoke these passages. Yet all of this intermixing takes places by divine agency. Thus Paul creates an image with something to shock both Gentile and Jewish Christians alike as they are bound together by God’s common purpose through an act described as "contrary to nature." In order to understand the full import of this phrase, it is essential to turn to the Greek text to examine a pattern obscured in the various English translations.
The Greek word physis, from which we derive the English words physical and physics, is often translated as "nature" or "the nature of things," describing conditions or circumstances as determined by birth or a regular or established order of things (Danker 1069-1070). The noun form physis occurs seven times in Romans, while the adjectival form physikos complements this usage another two times in chapter one. By contrast physis is used only three times within the remainder of the undisputed Pauline corpus. The frequency with which the word appears in Romans would seem to denote a significant concept for Paul as he writes to the Roman church. To understand the importance of physis within Paul’s argument it is necessary to work through the letter, examining the contexts in which the word appears.
In Romans 1:18 32 Paul’s rhetorical spokesman delivers a polemical speech about Gentile idolatry and the consequences of God’s wrath, describing pagan women who have exchanged their "natural use" (tēn physikēn chrēsin) for that which is unnatural (para physin) and men who have abandoned the natural use (tēn physikēn chrēsin) of women. Their behavior is the result of "degrading passions" (pathē atimias) that lead to "shameless acts" (aschēmosunē ), suggesting their actions para phusin are not value neutral. Though Paul stops just short of calling this sin, his characterization is undoubtedly negative.
Two other uses of physis occur in chapter two. First in 2:14, Paul discusses Gentiles who do not possess the law, but "do instinctively (physei) what the law requires" in the NRSV or "do by nature (physei) the things contained in the law" (KJV). Here, physis is used in the dative case, conveying "by means of which." While the King James consistently renders this word as "nature," modern translations often opt for other words, thus obscuring the connection between this passage and the usage in Romans 1:26.  Following this in 2:26-27 Paul returns to the concept of nature again:
Here several modern translations use the related word "physically," while the King James renders the phrase as "uncircumcision, which is by nature." Again the word choice in most modern translations obscures the connection with previous occurrences of the word.
Returning to the olive tree metaphor in chapter 11, Paul uses the Greek word physis four times. In three instances Paul describes the state of Jewish and Gentile branches as cultivated and wild respectively, using the phrase "according to nature" (kata physin). In the fourth occurrence, Paul asserts that the uncultivated Gentile branch has been engrafted into the olive tree "contrary to nature" (para physin). Though he is not explicit in his reference, the agency responsible for this engrafting is clearly God.  While some commentators insist that there is no indication of moral failing or ethical dilemma in God’s actions, the allusions to Levitical law do not support this assertion.  At least for the Jewish hearers of Paul’s metaphor, God’s actions are both shocking and questionable in the light of the Law.
Thus, while the relationship between these passages is not readily visible in most modern English translations, a logical connection between them, based on the frequent repetition of physis that is unique to Romans, nonetheless exists:
Chapter 1 Paul attributes acts to Gentiles that are "contrary to nature" (para physin).
Chapter 2 Paul glosses the "natural" attribute of the uncircumcised Gentile. Though not explicitly stated, the text implies that those who are circumcised as a sign of inclusion within the covenant have been made so contrary to nature.
Chapter 11 Paul specifically points out Gentile branches are by nature (kata physin) wild and that Jewish branches are by nature (kata physin) a part of the cultivated olive tree. In contrast, God has acted against nature (para physin) by mixing the two, grafting the wild (uncircumcised) branch into the cultivated tree.
Paul’s deconstruction travels a trajectory from pagan practices contrary to nature, through covenant practice that is contrary to nature (but still performed by human beings), to God’s own action that is contrary to nature. While modern English translations make the connections difficult to see, they are clear within the Greek text. By implicating God in an act that is also contrary to nature, Paul appears to take the sting out of the polemical reference to Gentile sexual practices acts in chapter one – surely good news, as Thomas Hanks points out, to the slaves within the Roman congregation whose choices in life were limited to submitting to homosexual acts initiated by their masters or facing death (587).
Concluding this reading I offer the beginning of a queer interpretation for the olive tree metaphor. As the rhetorical trap in Romans 1 has been read and accepted at face value over the centuries within the Christian context, queer people have been derided as unclean, sinful and depraved. This passage has been used as the clearest New Testament condemnation of same-sex behaviors and as justification for the maiming and killing of countless people who either cannot pass for the heterosexual norm or have chosen homogenital activity in physical expression. Yet on closer examination, we find that Paul’s rhetorical speaker uses categories and images that Paul himself deconstructs in subsequent passages of his letter. Unclean Gentiles are not the only ones who perform acts contrary to nature. It would appear that in observing the covenant of circumcision the chosen ones are also acting contrary to nature. But according to Paul, so does the very God that the chosen ones worship. Secondly, gays, lesbians, bisexuals and transgendered (LGBT) people are notorious in much of the Christian world (and arguably beyond) for our alleged non-productive nature. Though families living openly with both biological and adopted children are chipping away at this stereotype, we are still seen as sterile or unable to procreate. And yet, God has chosen to engraft even us, the wild ones, into the rich root of the cultivated tree. We too participate in the growth that has sprung forth from the root of Abraham and are part of the living trajectory of God’s work in the world. And through our own subversion of cultural norms, queer folk point to the otherwise unnoticed acts of our society that seem natural, however contrary to nature they may be. But moreover, our witness within the trajectory of the faith points to the hand of an unseen God who, quite contrary to the notions of some, has engrafted us firmly into the living tree. Though we are different, we share in the call of joint identity in the blessing of Abraham.
 While the exegetical work I will present in this paper was developed in parallel to similar arguments presented by several authors who have explored the use of kata physin and para physin in Romans, I owe the term "deconstruction" to the work of Thomas Hanks in his contribution to the Queer Bible Commentary (582).
 Richard Hays suggests that in Romans 1 the phrase has a moral judgment, while Paul "artfully plays" the meaning of "artificial" as counterpoint against his previous usage (199).
Selected Scriptural Passages with the Root physis
These following passages are presented in the New American Standard because of the word to word correlations provided by the more literal translations:
NAS Romans 1:26 ¶ For this reason God gave them over to degrading passions; for their women exchanged the natural function (tēn physikēn chrēsin) for that which is unnatural (para physin), 27 and in the same way also the men abandoned the natural function (tēn physikēn chrēsin) of the woman and burned in their desire toward one another, men with men committing indecent acts and receiving in their own persons the due penalty of their error.
NAS Romans 2:12 ¶ For all who have sinned without the Law will also perish without the Law; and all who have sinned under the Law will be judged by the Law; 13 for not the hearers of the Law are just before God, but the doers of the Law will be justified. 14 For when Gentiles who do not have the Law do instinctively (physei) the things of the Law, these, not having the Law, are a law to themselves, 15 in that they show the work of the Law written in their hearts, their conscience bearing witness, and their thoughts alternately accusing or else defending them, 16 on the day when, according to my gospel, God will judge the secrets of men through Christ Jesus. 17 ¶ But if you bear the name "Jew," and rely upon the Law, and boast in God, 18 and know His will, and approve the things that are essential, being instructed out of the Law, 19 and are confident that you yourself are a guide to the blind, a light to those who are in darkness, 20 a corrector of the foolish, a teacher of the immature, having in the Law the embodiment of knowledge and of the truth, 21 you, therefore, who teach another, do you not teach yourself? You who preach that one should not steal, do you steal? 22 You who say that one should not commit adultery, do you commit adultery? You who abhor idols, do you rob temples? 23 You who boast in the Law, through your breaking the Law, do you dishonor God? 24 For "the name of God is blasphemed among the Gentiles because of you," just as it is written. 25 ¶ For indeed circumcision is of value, if you practice the Law; but if you are a transgressor of the Law, your circumcision has become uncircumcision. 26 If therefore the uncircumcised man keeps the requirements of the Law, will not his uncircumcision be regarded as circumcision? 27 And will not he who is physically uncircumcised (hē ek physeōs akrobustia), if he keeps the Law, will he not judge you who though having the letter of the Law and circumcision are a transgressor of the Law? 28 For he is not a Jew who is one outwardly; neither is circumcision that which is outward in the flesh. 29 But he is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit, not by the letter; and his praise is not from men, but from God.
NAS Romans 11:21 for if God did not spare the natural branches (tōn kata physin kladōn), neither will He spare you. 22 Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if you continue in His kindness; otherwise you also will be cut off. 23 And they also, if they do not continue in their unbelief, will be grafted in; for God is able to graft them in again. 24 For if you were cut off from what is by nature a wild olive tree (ek tēs kata physin eksekopēs agriela), and were grafted contrary to nature (para physin) into a cultivated olive tree, how much more shall these who are the natural branches (hoi kata physin) be grafted into their own olive tree?
Byrne, Brendan. Romans. Collegeville, Minnesota: Liturgical Press, 1996.
Danker, Frederick William, ed. A Greek-English Lexicon of the New Testament and Other Early Christian Literature. 3rd Edition. Chicago: University of Chicago Press, 2000.
Davies, William David. Jewish and Pauline Studies. Philadelphia: Fortress Press, 1984.
Dunn, James D. G. World Biblical Commentary: Romans 9-16. Nashville: Thomas Nelson Publishers, 1988.
Esler, Philip F. "Ancient Oléiculture and Ethnic Differentiation: the meaning of the olive-tree image in Romans 11." Journal for the Study of the New Testament (2003): 103-124.
Fitzmyer, Joseph A. Romans: a new translation with introduction and commentary. New York: Doubleday, 1993.
Hanks, Thomas. "Romans." The Queer Bible Commentary. Ed. Deryn Guest. London: SCM, 2006. 582-605.
Hays, Richard B. "Relations Natural and Unnatural: a response to John Boswell’s exegesis of Romans 1." The Journal of Religious Ethics 14 (1986): 184-215.
Based on this feedback from the professor and a follow-up conversation, I have added to this version of the essay a footnote crediting Thomas Hanks with helping me to understand previous exegetical work that I had independently undertaken.
Though I had previously completed the lemma searches that produced the information regarding the use of physis in this essay, it was Hanks’ insight regarding Paul’s audience of slaves and his use of the language of "deconstruction" that helped me to connect the dots in the way that I’ve presented here.