What follows is based on ‘The problem of sensus plenior’, by Douglas Moo (chapter 5 of Hermeneutics, Authority, Canon, edited by D.A. Carson and J.D. Woodbridge (Grand Rapids: Zondervan, 1986).  Moo’s chapter is available here.

A belief in the entire truthfulness and trustworthiness of Scripture raised a number of questions.  One question is this: ‘How can we accord complete truthfulness to [the New Testament] writings that appear to misunderstand and misapply those [Old Testament] texts from which they claim to derive authority and rationale for their most basic claims and teaching?’

Historical sketch

Some, such as Marcion in the ancient church, and Harnack more recently, have side-stepped the problem altogether by effectively jettisoning the Old Testament as Scripture.

Others, such as Origen, have taken refuge in allegorisation, using it as a tool with which to force a ‘spiritual’ meaning on an Old Testament that seemed otherwise to be incompatible with Christian belief.

At the time of the Reformation, Luther, Calvin and others rejected the allegorical approach.  They insisted on the ‘literal’, grammatico-historical meaning of the biblical text, and claimed back for the Old Testament and its people a real spiritual experience, not viewing it simply as a quarry for Christian symbolism.

After the Reformation, the allegorical approach was not entirely lost, and even in Protestant circles there was a keen interest in typology.

With the development of ‘scientific’ historical exegesis, scholars began to question whether the way the New Testament used the Old Testament was itself valid and authoritative.  They often allowed their own interpretations of the Old Testament to ‘trump’ those of the New Testament writers.

In reaction to the methods and conclusions of the ‘higher criticism’, some scholars began to re-assert the unity of the Bible, telling its story as ‘salvation history’.  The two testaments were related to one another as anticipation and realisation.  On the Roman Catholic side, John H. Newman sought to resist what he saw as the over-rational approach of many critics and to re-instate the ‘mystical’ sense of Scripture as the divinely-intended meaning.

Approaching the problem

Where difficulty is experienced in understanding, by modern exegetical methods, how the New Testament writers have arrived at a particular interpretation of an OT text, some take a fideistic approach.  This says, essentially, ‘Who am I to question what divinely-inspired apostles have written?’  Although this attitude demonstrates reverence and some good sense, as a complete answer it is unsatisfactory, because it invites us to leave our God-given minds unused.  Moreover, we would still need to use those God-given minds, and the exegetical methods they have discovered, in order to determine the meaning of the New Testament texts, and so the problem is still not removed.  And, in any case, the use of the Old Testament by the New is too basic to our own identity as the people of God for us to be able to leave in the realm of unexplained assertion.  How can the Christian church validate the claim that its Lord is the completion and fulfilment of the OT scriptures if it cannot show that this conclusion best accords with the meaning of the OT?

Other adopt a subjective approach to the problem.  Here, there is a denial of a ‘correct’ meaning in the text, and the meaning one ascribes depends largely on the presuppositions one brings to it.  The strength of this approach is, of course, that it recognises the presence and importance of the reader’s presuppositions, and in prompts him or her to make allowances for them.  But the interpretative circle is not a closed one: we can and should break into it by seeking to discover ‘real’ meaning in the text.

Rejecting the fideistic and subjective approaches as inadequate, we turn again to the question of whether certain New Testament interpretations are ‘really in’ the OT texts themselves.

Defining the problem

We move towards a clear definition of the problem by recognising that (contrary to the beliefs of some critics) the vast majority of those who believe in the complete truthfulness and trustworthiness of Scripture do not hold to a mechanical theory of inspiration.  The definition of the problem is also clarified by acknowledging that the NT writers quote the OT in a variety of ways, and for a variety of purposes.  Not all of these require absolute faithfulness to the original context.

Sometimes, a NT speaker or writer will use OT language as a vehicle to express his or her own thoughts.  When Jesus says, ‘My soul is sorrowful, even unto death’ (Mk 14:34; Mt 26:38) he is probably alluding to Psalms 42 and 43.  But that does not mean that Jesus is necessarily viewing those psalms as prefiguring his own sufferings and death.  Paul’s use of Deut 19:15 in 2 Cor 13:1 is a similar example.

In other cases, the NT speaker or writer may be legitimately extending the meaning of the OT text.  The application made of the text still falls within the original author’s general meaning.  Thus, Paul’s point in 1 Cor 9:9 is a legitimate application of Deut 25:4.

In still other cases, the NT writer may be referring other people’s understandings or uses of the OT texts cited.  Those texts have, with or without modification, become ‘slogans’ to support some mistaken belief or action.  Examples are found in the antitheses of Matthew 5, esp. Mt 5:43.  Sometimes, as in the verse just cited, the context clearly indicates what is going on.  Something similar may be happening, however, in other places, where the context is not so decisive (see Paul’s use of Lev 18:5; Gal 3:12, 21; Rom 10:5).

Then again, we should understand how the language of ‘fulfilment’ is used in the NT.  The use of Hos 11:1 in Mt 2:15 does not mean that, according to Matthew, Hosea predicted the flight of the holy family to Egypt and their subsequent return.  Matthew can see as clearly as we can that Hos 11:1 is a statement of historical fact, and not a prediction of the future.  He may well mean that Jesus, God’s ‘greater Son’, fulfils, or brings to completion, the ‘Exodus’ motif that had become, even in the OT, an eschatological theme.

Proposed solutions

The most popular explanation for the way the NT uses the OT is that it uses methods that were usual in Jewish exegesis of that time.  But some of these methods sometimes lead to inappropriate or even fantastical interpretations, and, in any case, there is some doubt about the extent to which the NT writers did use these methods.  Still, this is not to invalidate those methods altogether, or to deny that the NT writers made any use of them.  But we will need to look further before we can determine whether the NT writers were ‘correct’ in their interpretations and applications of the OT.

In recent decades typology has re-emerged as a scholarly interest.  Simply put, a ‘type’ is an example or pattern.  Typology assumes that that God acts in similar ways in both testaments, and that there can therefore be real correspondence between them.  What is less certain, however, is whether the type actually predicts the antitype, or it is just the case that the antitype looks back at the type, drawing out resemblances.  Perhaps it is best to see typology within the larger context of promise and fulfilment.  If the OT looks forward to the coming of Christ, then it is reasonable to suppose that NT persons, events and institutions ‘fill out’ the OT picture, completing what had previously been sketched.  But does typology have a predictive element?  To take one example: if we understand David to be the author of Psa 22, then we can see that his experiences recorded in that psalm anticipate those of his promised progeny.  A typological approach understands Jesus as the ultimate ‘fulfilment’ of David’s experience in that psalm.  Typology is already apparent within the OT, with its repeated use, for example, of the Exodus motif; but there are probably other instances of predictive types, even where the prospective element was not clearly recognised at the time.

Dealing with the problem through theological exegesis

Walter Kaiser is convinced that it would have been illegitimate for a NT author to impute a different meaning to an OT text than the original author intended.  Nevertheless, he thinks that careful exegesis can resolve apparent discrepancies between the meaning of the OT text and the meaning given to that text in the NT.  But whether this works for all the texts in question is disputed.  For example, Kaiser says that the meaning of Hos 11:1 that is assumed in Mt 2:15 (that ‘my son’ has a technical meaning, with implications for corporate solidarity) must have been there in the original, but this may be stretching the point.

This procedure becomes problematic in that series of texts where OT passages that speak of Yahweh are in the NT applied to Christ (see, for example, Rom 10:13/Joel 2:32).  While this is perfectly understandable from the viewpoint of NT theology, can we really say that Joel ‘intended’ his prophecy to apply to Christ?

Sensus plenior

According to this concept, an OT text may have a ‘fuller meaning’, intended by God, as ultimate author of that text, though not fully perceived by the original human writer.  This ‘fuller meaning’ cannot, therefore, be elicited by the use of traditional grammatical-historical exegesis of the original text, but is discovered under the light of further revelation.  (For Roman Catholic scholars, such as Raymond Brown, the ‘fuller meaning’ could also be discovered through the church’s magisterium).

Various questions and objections might be raised.  Could any OT text have a ‘fuller meaning’, or should we limit the concept to include only those texts that are explicitly given a sensus plenior in the NT?  Would NT quotations of OT texts not lose their apologetic value for their original Jewish readers if they poured novel meanings into those texts?  How does the concept fit with a concursive understanding of inspiration? (In partial answer to this last question, the case of Caiaphas in Jn 11:49-52 shows that a human agent may indeed speak or write more truly than he himself knows).

Scholars such as Brown and Packer insist that a ‘fuller meaning’ would be ‘more than’, but not ‘other than’, the original meaning of the text.

A canonical approach

Some who favour a canonical approach see little utility in a doctrine of sensus plenior.  Reading an OT text in its canonical context, they claim, allows us to take into account the NT understanding of that text.  this is consistent with a redemptive-historical framework, in which the whole of the OT points forward to Christ (Mt 11:13; Rom 10:4).  If, Jesus ‘fills up’ Israel’s law, Mt 5:17, history, Mt 2:15, and prophecy, Acts 3:18, then it is reasonable to think that he also ‘fills up’ the meaning of many specific OT texts.  This process of the later ‘filling up’ the earlier can be seen even within the pages of the OT itself (with the concepts of the Exodus, for example, and of the Davidic king, taking on increasing significance).  It would not be surprising, then, to find the process continuing into the NT.  As God’s plan unfolds, a meaning that was at first pregnant in the text takes on a deeper significance.  We can at least in part validate this deeper meaning through our own exegesis, while recognising that both the OT and the NT writers were enabled by a divine inspiration that is not available to us.

1 Cor 15:27 (citing Psa 8:6) can be understood in this light.  The ‘man’ of Psa 8:5 is clearly the generic or representative man.  Paul sees Christ as the ‘second man’, the perfect man, the man prefigured by Adam and now realised in Christ.  The psalm itself gives no indication of the significance that would later be given to it, and yet Paul’s meaning was latent in the text and now become clear in the light of who Christ is.

Hab 2:4b is cited in Rom 1:17 and Gal 3:11 in connection with Paul’s doctrine of justification by faith.  The Hebrew (MT) text of the original has a third person possessive (‘the righteous one shall live by his [own] faith’, whereas the Greek (LXX) has a first person possessive (‘the righteous one shall live by my (the Lord’s] faith/faithfulness’).  Paul, however, omits any possessive pronoun, probably because he wishes to emphasis that faith is the gift of God, and not a human possession or quality.  Paul, then, is actually modifying the text in order to bring out a particular meaning.  In fact, Paul’s entire presentation of the quote seems designed to bring out his distinctive understanding of ‘righteousness’, ‘faith’ and ‘life’.  The original text is pregnant with these meanings, even though we cannot say that they were consciously intended by the prophet himself.  The text is given ‘an added depth, a new richness, a more precise significance in the light of the “revelation of the righteousness of God” (Rom 3:21).’

Conclusion

No single formula explains how NT writers find additional meaning in some OT texts.  Our starting point is the divine inspiration and canonical status of all Scripture.  Typology, progressive revelation culminating in Christ, and the traditional sensus plenior model all help to explain specific cases.  While we cannot always ‘prove’ that the interpretation put upon a text by a NT writer is a valid one, our doctrine of inspiration should be sufficiently robust for us to accept that interpretation.  And, while our own exegesis can be informed by the ways in which the NT authors use the OT, we should be cautious about suggesting ‘deeper meanings’ where there is no clear enunciation of these in Scripture.