The question of how "adoption" as used metaphorically by Paul relates to modern notions of adoption is not as important as comparing it to other ancient understandings. Once this is in place, however, the further comparison of the concept from Roman antiquity with modernity (in industrialized West, by implication?) can benefit from those findings.
Although Romans 8 is picked out for comment in the question, in fact the explicit language of "adoption" is infrequent in the New Testament. The key term in Greek is υἱοθεσία (huiothesia); it occurs in the NT only in the following texts (English is from the ESV; Greek is Nestle-Aland 27):
- For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption <...>, by whom we cry, "Abba! Father!"
- οὐ γὰρ ἐλάβετε πνεῦμα δουλείας πάλιν εἰς φόβον ἀλλὰ ἐλάβετε πνεῦμα υἱοθεσίας ἐν ᾧ κράζομεν· αββα ὁ πατήρ.
- And not only the creation, but we ourselves, who have the firstfruits of the Spirit, groan inwardly as we wait eagerly for adoption <...>, the redemption of our bodies.
- οὐ μόνον δέ, ἀλλὰ καὶ αὐτοὶ τὴν ἀπαρχὴν τοῦ πνεύματος ἔχοντες, ἡμεῖς καὶ αὐτοὶ ἐν ἑαυτοῖς στενάζομεν υἱοθεσίαν ἀπεκδεχόμενοι, τὴν ἀπολύτρωσιν τοῦ σώματος ἡμῶν.
- They are Israelites, and to them belong the adoption, the glory, the covenants, the giving of the law, the worship, and the promises.
- οἵτινές εἰσιν Ἰσραηλῖται, ὧν ἡ υἱοθεσία καὶ ἡ δόξα καὶ αἱ διαθῆκαι καὶ ἡ νομοθεσία καὶ ἡ λατρεία καὶ αἱ ἐπαγγελίαι
- ...to redeem those who were under the law, so that we might receive adoption <...>.
- ...ἵνα τοὺς ὑπὸ νόμον ἐξαγοράσῃ, ἵνα τὴν υἱοθεσίαν ἀπολάβωμεν.
- ...he predestined us for adoption <...> through Jesus Christ, according to the purpose of his will,...
- ...προορίσας ἡμᾶς εἰς υἱοθεσίαν διὰ Ἰησοῦ Χριστοῦ εἰς αὐτόν, κατὰ τὴν εὐδοκίαν τοῦ θελήματος αὐτοῦ,
Textual note: In the ESV given above, places marked
<...> have the phrase "as sons" which has been supplied in translation; note its absence from Rom 9:4. It is not a quirk of the ESV, but was introduced into this translation tradition by the RSV, and something like it is also in the NIV, NASB, and a bevy of derivatives. As it happens, the simple "...Spirit of adoption, whereby..." (in Rom 8:15) or the like is found in the KJV, ASV, NRSV, ISV, HCSB, and NET, among others. I concur with Cranfield that the phrase "of sonship" is implied, but best omitted as a translation equivalent.1
So, only five verses, then, three of which are in Romans. Four of them apply the concept to those in Paul's churches (i.e., to Christians). The "odd one out" is Romans 9:4 which sees "adoption" as a property of Paul's "own people", i.e. the Jews.2
However, our interest is not so much in the nuances meaning across these texts, but rather how the concept of "adoption" as practised in Roman antiquity informs them all.
Adoption in Antiquity
Sanday and Headlam's (frankly disappointing) treatment of this theme suggests that the term huiothesia is of Pauline coinage.3 This is not the case. Its frequent use in inscriptions is noted even in the brief entry in the Liddell-Scott-Jones Greek-English Lexicon. So this is not a particularly "Pauline" term in that sense, although he is the only one to put it to use in the Greek scriptures.
The explicitly legal aspect of huiothesia was explored in a pair of articles by Francis Lyall (a professor of Law rather than NT): "Metaphors, Legal and Theological", Scottish Bulletin of Evangelical Theology 10/2 (1992): 94-112; and his earlier article devoted to this theme, "Roman Law in the Writings of Paul: Adoption", Journal of Biblical Literature 88/4 (1969): 458-466.4 I draw liberally on his work in what follows.
Lyall defines "adoption" as
the legal device found in many legal systems by which a person leaves his own family and enters the family of another.
And this device is used typically to ensure continuity of the family line ("Roman Law", p. 459). Most important is Lyall's contention that Roman law, in distinction from Jewish law (an obvious source for Paul) or even Greek law provides the necessary context for understanding the metaphor as used in the Pauline epistles. In the case of Jewish law, he argues (at length in the JBL article) that it included other measures to achieve the aim of continuity of the line, and so "adoption" was foreign to it. While there may, in fact, be potential parallels in ancient Near Eastern law (Nuzi in particular), these are much too remote from Paul to be meaningful parallels for his usage. On the other hand, Greek law offers only "a pale shadow of the Roman, existing more as a succession device than anything else" ("Roman Law", p. 465).
But Paul was also a Roman citizen, and was under jurisdiction of Roman law.5 Roman law knew several technical variations on the legal device, but the two leading forms
have the same fundamental effect. The adoptee is taken out of his previous state and is placed in a new relationship with his new paterfamilias. All his old debts were cancelled, and in effect he starts a new life. From that time the paterfamilias owns all the property and acquisitions of the adoptee, controls his personal relationships, and has rights of discipline. On the other hand, he is involved in liability by the actions of the adoptee and owes reciprocal duties of support and maintenance.
("Roman Law", p. 466.) Or, put in slightly different terms in "Metaphors, Legal and Theological", p. 106:
In Roman law adoption meant that one entirely ceased to be a member of one's own former family and came under the power and authority of a new head of family, the paterfamilias.
This Roman conception of "adoption", Lyall concludes, provides a sufficiently cogent parallel to Paul's context, and only the Roman form has this quality.
This differs from most of the other forms of ancient adoption which were rather an instrument for familial continuity, or indeed from modern forms of adoption which tend to involve orphan care and/or bringing children into a home where biological offspring are not possible. (I simplify greatly here.)
Although other commentators broaden the associations beyond Lyall's strict bounds, the main outlines of his case are often discernible.6 Cranfield's highly regarded and dense presentation of the material, replete with classical sources, provides one such example.7 Fundamentally, the legal transfer of domestic identity lies at the heart of Roman adoption.
- C.E.B. Cranfield, Romans 1-8 (ICC; Edinburgh, 1975), p. 398, n. 1
- And to confirm explicitly, it is absent from the Septuagint, in spite of something like "adoption" being found in Genesis 15 and Esther 2, and perhaps a few other places. Lyall (see below) discusses a number possible precedents from the Hebrew Bible; see also note 7.
- W. Sanday & A.C. Headlam, A Critical and Exegetical Commentary on the Epistle to the Romans, 5th edn (ICC; T & T Clark, 1902), p. 203. At three other points in the commentary they refer the reader back to this discussion, minimalist as it is. I feel like I must be overlooking something obvious, but I'm fairly sure I'm not.
- It might amuse and/or interest some BH.SErs to know that he also "published five crime novels and edited nine collections of science fiction"! His more relevant work to this Q&A is his Slaves, Citizens, Sons: Legal Metaphors in the Epistles (Academie Books, 1984).
- Lyall cites J.S. Candlish, "Adoption", in A Dictionary of the Bible..., ed. by James Hastings et al (Edinburgh: T & T Clark, 1898), vol. 1, pp. 40-42, as helpfully incorporating attention to Roman adoption law in explaining Pauline usage. The later and larger Encyclopædia of Religion and Ethics, also edited by Hastings (and also Edinburgh: T & T Clark, 1908 - but now in 12 volumes, plus an index volume) has seven connected articles on "adoption" in various cultures and contexts; "Adoption (Roman)" by W.J. Woodhouse is found in vol. 1, pp. 111-114.
- Lyall's case is broadly followed by, e.g., J.A. Fitzmyer, Romans (Anchor Bible; Doubleday, 1992), p. 500.
- Cranfield, Romans 1-8, pp. 397-398; J.D.G. Dunn, Romans 1-8 (Word Biblical Commentary; Thomas Nelson, 1988), p. 452 simply refers his readers to "Cranfield's excellent note"!