Summa Theologiae III.42.4 – a question of ‘salvation-history’

At the outset of III.42.4 Aquinas proposes three reasons why Christ might have been expected to write a book. Interestingly, none of these touches directly on the question of eliminating the possibility of heresy or schism (perhaps Thomas's experience of university theology persuaded him that schoolmen could argue over anything, including a dominical text). The first reason suggested is that ‘the purpose of writing is to hand down doctrine to posterity’, and that, as Christ's doctrine is destined to last forever (‘heaven and earth shall pass away, but my words shall not pass away’– Luke 21:33), it needed to be committed to writing so that it could be handed down.Footnote ³ The second argument is based on the idea that, as the Old Law which foreshadowed Christ was written, the New Law which fulfilled the Old should equally have been written.Footnote ⁴ Finally, Aquinas proposes that ‘to Christ, who came to enlighten those that sit in darkness (Luke 1:79), it belonged to remove occasions of error, and to open out the road to faith’– a reference, as a close reading of the objectio reveals, not to the prevention of heresy and schism, but to the conversion of the Gentiles within the specific context of primitive Christianity.Footnote ⁵ In fact, these three arguments have nothing whatsoever to do with what modern readers might think of as the obvious advantages of Jesus writing a book, and have everything to do with questions of salvation-history – with the transition from the Old Law to the New Law, with the preaching of the gospel to the Gentiles, and with the traditio of Jesus's everlasting teaching.

In his replies to these objections, Aquinas accepts the salvation-historical premise but disputes the idea that the unfolding of salvation-history would have been best served by Jesus writing a book. To the argument that such a book would have facilitated the process of traditio, he counters (citing Augustine) that the disciples were the members of Christ's body, and that, taught by him and acting as his ‘hands’, they ‘wrote whatever he wished us to read concerning his deeds and words’.Footnote ⁶ To the argument that, since the Old Law was written, the same should apply to the New Law, Aquinas replies that, whereas the Old Law was given under the form of sensible signs and therefore fittingly written with sensible signs, Christ's doctrine (the New Law) is ‘the law of the Spirit of life’ (Romans 8:2), which had to be ‘written not with ink, but with the Spirit of the living God, not in tables of stone, but in the fleshly tables of the heart’ (Aquinas is quoting 2 Corinthians 3:3).Footnote ⁷ Lastly, to the argument that a dominical book would have advanced the evangelization of the Gentiles, Aquinas answers that ‘those who were unwilling to believe what the apostles wrote of Christ would have refused to believe the writings of Christ’.Footnote ⁸ As in the original objections, questions of doctrinal clarity and of the exclusion of heresy and schism are not raised, and Aquinas's sole concern is with what was required by the unfolding of salvation-history.

In the corpus of the article, Aquinas advances three further reasons why Jesus should not have committed his doctrine to writing. The first of these relates to Christ's dignity, concerning which Aquinas observes ‘the more excellent the teacher, the more excellent should be his manner of teaching’. The argument that follows goes like this: (i) ‘writings are ordained, as to an end, unto the imprinting of doctrine in the hearts of the hearers’; (ii) the best teachers, such as Pythagoras and Socrates, accomplish this by the sheer power of their teaching without recourse to writing; (iii) ‘it was fitting that Christ, as the most excellent of teachers, should adopt that manner of teaching whereby his doctrine is imprinted on the hearts of his hearers’ in accordance with Matthew 7:29 –‘he was teaching them as one having power’.Footnote ⁹ Aquinas writes that ‘the power of Christ's teaching is to be considered in the miracles by which he confirmed his doctrine, in the efficacy of his persuasion, and in the authority of his words, for he spoke as being himself above the Law … and, again, in the force of his righteousness shown in his sinless manner of life’.Footnote ¹⁰ This idea of imprinting doctrine on hearts clearly picks up on the response to the second objection where the focus is on the idea that the New Law was to be written on hearts, and points towards the discussion of the New Law in Summa Theologiae I-II.106.

The second reason why Jesus should not have written a book is ‘on account of the excellence of Christ's doctrine, which cannot be expressed in writing’, in support of which Aquinas quotes John 21:25 –‘There are also many other things which Jesus did, which, if every one were written, the world itself, I think, would not be able to contain the books that should be written’. Citing Augustine, he interprets this text as referring not to the volume of Christ's teaching, but to the fact that his teachings far exceeded the capacity of any potential readers to understand them. Aquinas concludes that ‘if Christ had committed his doctrine to writing, people would have had no deeper thought of his doctrine than that which appears on the surface of the writing’. Written today, such a statement would probably be taken as referring to the gulf between the author's intention and the reader's interpretation, but this is unlikely to be what Aquinas has in mind. For Aquinas it is this particular kind of teaching – the teaching of someone who imprints his doctrine on hearts – that eludes understanding, and not written texts in general. This argument possibly picks up on Aquinas's response to the third objection, in which he suggests that a dominical book would not have advanced the preaching of the gospel to the Gentiles.

The third reason why Jesus should not have written a book is in order that ‘his doctrine might reach all in an orderly manner’. Aquinas understands this ‘orderly manner’ (ordine quodam) as consisting in Jesus ‘teaching his disciples immediately, and they subsequently teaching others, by preaching and writing’, as opposed to Jesus writing himself, in which case ‘his doctrine would have reached all immediately’– which would (as we shall see) not have constituted an orderly manner – and backs this up with a quotation from Proverbs 9:3 to the effect that Wisdom ‘has sent her maids to invite to the tower’.Footnote ¹¹ There is a clear reference in all this to the response to the first objection, in which is it asserted that Jesus's teaching was properly passed on by his disciples, who taught as members of his mystical body, and were, in effect, the hands that wrote on behalf of Christ the head.

The three arguments proposed in the corpus, accordingly, correspond (in varying degrees of explicitness) with those put forward in the responses to the objections, and relate to the advancement of salvation-history through (respectively) the transition from Law to Gospel, the evangelization of the world, and the orderly traditio of Jesus's everlasting teaching. In what follows I intend to examine the way in which Aquinas explores these various ideas elsewhere in the Summa, and, in the process, to underline further the reasons why, for salvation-historical reasons, it was necessary that Jesus should be a preacher rather than a writer.

The excellence of Christ as teacher

Central to the argument of III.42.4 is the idea that ‘the more excellent the teacher, the more excellent should be his manner of teaching’, and that Jesus accordingly did not commit his doctrine to writing but imprinted it directly on hearts. This insight derives from Jeremiah 31:31–33 and especially Hebrews 8:8,10 –‘this is the covenant I will make with the house of Israel after that time, declares the Lord. I will put my laws in their minds and write them on their hearts’ (Hebrews 8:10).Footnote ¹² Aquinas sets this text alongside others such as Romans 8:2 (‘The law of the spirit of life, in Christ Jesus, has delivered me from the law of sin and of death’), and, following Augustine's interpretation in his De Spiritu et Littera, concludes that (i) the Old Law was written on tablets of stone whereas the New Law is written on hearts, and (ii) the New Law that is written on hearts is nothing other than the presence of the Holy Spirit.Footnote ¹³ He acknowledges that ‘the New Law contains certain things that dispose us to receive the grace of the Holy Spirit, and pertaining to the use of that grace’ which need to be put into writing, but it remains the case that the New Law is primarily ‘a law that is inscribed on our hearts’.Footnote ¹⁴ The New Law, accordingly, is primarily a ‘reality in people’.Footnote ¹⁵ Above all, it is a reality which establishes us in charity and friendship with God,Footnote ¹⁶ and which enables us to perform God's will out of love rather than out of fear.Footnote ¹⁷ Charity is necessarily free and spontaneous – something that rises up within us rather than coming to us from a book (even if that book is the Bible) – and Christ teaches us how to love by a doctrina that is interior and immediate and productive of caritas.Footnote ¹⁸

Taking his lead from 2 Corinthians 3:6 (‘the letter kills, but the spirit gives life’), Aquinas contends that the written part of the New Law, which includes those teachings of faith and moral precepts which are contained in the New Testament, ‘would kill unless there were the inward presence of the healing grace of faith’, and emphasizes that the chief element is always ‘the grace of the Holy Spirit bestowed inwardly’.Footnote ¹⁹ The giving of the New Law represents the culmination of the history of salvation,Footnote ²⁰ and the perfect ‘state’ of the New Law will endure until the end of the world.Footnote ²¹ Matthew Levering suggests that, for Aquinas, the grace of the Holy Spirit in which the New Law consists represents the final fulfillment of Torah and Temple, and enables us to participate in Christ's own fulfillment of the Law which is itself made possible by his own fullness of grace.Footnote ²² The implications of this for the question ‘why didn't Jesus write a book?’ are clear. Had Jesus done so, he might have offered an authoritative account of the teachings of faith and of the moral precepts, but, even as written by him, these would still have been ‘the letter that kills’. In order for Jesus to move salvation-history forwards to its final and perfect state, he needed to teach in the only way that would justify and bring life – namely, by fulfilling the promises of Jeremiah 31:31–33 and imprinting God's New Law, which is nothing other than the grace of the Holy Spirit, on human hearts.

So how does Christ write the New Law – the grace of the Spirit – onto hearts? First of all, Aquinas explains that it is God who does the writing: ‘it is as necessary that God alone should deify, bestowing a partaking of the divine nature by a participated likeness, as it is impossible that anything save fire should enkindle’.Footnote ²³ Secondly, he does the writing through the medium of Christ's human nature which is joined to the Godhead of the Son.Footnote ²⁴ Thirdly, he does the writing through the sacraments which are an extension of Christ's humanity: ‘in the sacraments of the New Law, which are derived from Christ, grace is instrumentally caused by the sacraments, and principally by the power of the Holy Spirit working in the sacraments’.Footnote ²⁵ The sacraments ‘derive their power (virtus) from Christ's passion’,Footnote ²⁶ and the power of the passion is applied to us (through the kind of faith that is rendered ‘living’ by charity) ‘not only as to the intellect, but also as to feeling (quantum ad affectum)’.Footnote ²⁷ A kind of divine energy, which is sacramentally appropriated through faith in the passion, is poured into our hearts and minds, and it is above all in applying the ‘divine power’ of the passion to us in this way that Jesus fulfils his vocation as teacher and preacher and writes God's New Law on human hearts. This virtus is nothing other than that power of the Holy Spirit which operates through the sacraments of the church to produce the gifts and fruits of the Spirit described in 1-2.68-70,Footnote ²⁸ and it is this vital power (rather than the dead letter of a written law) in which the New Law primarily consists.

Aquinas interprets Galatians 2:21 (‘if justification comes from the Law then Christ died in vain’) as meaning that, if justifying grace were caused by the sacraments of the Old Law, there would have been no purpose in Christ dying and communicating to us the virtus of the passion through the medium of the sacraments of the New Law.Footnote ²⁹ From this it follows that, precisely because the Old Law was a law written on tablets of stone as opposed to a law written on hearts, its sacraments ‘were not endowed with any power by which they conduced to the bestowal of justifying grace, and they merely signified faith by which human beings were justified’. The sacraments of the Old Law had the exterior capacity to elicit justifying faith (inasmuch as they pointed towards the passion), but only the sacraments of the New Law possess the interior power to cause grace – that divinizing ‘participated likeness of the divine nature’ which consists in the indwelling of the Holy Spirit.Footnote ³⁰

In effect, III.62 completes the argument begun in I-II.106 and carried on in III.49 according to which the role of Jesus is to write the New Law, which consists primarily in the grace of the Holy Spirit, on human hearts. He is able to achieve this because, in his human nature, he is the instrument of the divinity, and because, in the sacraments, he is able to apply directly to the hearts of believers the spiritual ‘power’ which flows through the sacraments in order to produce grace. The significance of this for the question ‘why didn't Jesus write a book?’ is clear. As we have seen, the first answer given to this question in 3.42 is that ‘the more excellent the teacher, the more excellent should be his manner of teaching’. For Aquinas, the fact that he is the incarnate Son of God establishes Jesus as the most excellent of all teachers, while his most excellent manner of teaching, his doctrina, is nothing other than the New Law – the grace and power of the Holy Spirit imparted in an interior manner. In fulfillment of Jeremiah 31:31–33 and Hebrews 8:8,10, Jesus writes his doctrina directly on hearts rather than on tablets of stone (or, indeed, paper), and he writes it with the sacraments of the New Law (which in turn derive their instrumental power from his passion) rather than with a pen.

The excellence of Christ's teaching

The second reason given by Aquinas in 3.42.4 to support his claim this Jesus should not have written a book is ‘on account of the excellence of Christ's doctrine, which cannot be expressed in writing’. As we have seen, the excellence of Jesus as a teacher consists in the fact that he teaches by producing the grace of the Spirit in hearts – from which it follows that, in one sense at least, the excellence of Jesus's doctrine consists in the fact that it actually is the grace of the Spirit. Of course, as Aquinas makes clear in 1-2.106.1, the New Law contains things which dispose us to receive the grace of the Spirit and to use that grace properly, and these are what we mean by Christ's doctrina in a secondary sense. Christ's doctrina in this secondary senses consists most obviously in his parables and precepts, but, more especially, in his actions.Footnote ³¹ Aquinas explains that ‘Christ's action is our instruction’,Footnote ³² and that ‘examples inspire better than words’,Footnote ³³ and this twofold principle informs everything that is said in the Tertia Pars about Christ's public life from the nativity and epiphany right through to the resurrection and the ascension, to the extent that every single action and event in the life of Jesus teaches us some theological, moral, spiritual or eschatological truth.Footnote ³⁴ At the same time, Aquinas constantly has in mind the principle laid down by Leo the Great that ‘unless he was God, he would not have brought a remedy; and unless he was man, he would not have set an example’,Footnote ³⁵ and integrates these two categories by showing how Christ's exemplary and instructive action (his doctrina in the secondary sense of the term) opens us up to his remedial and sacramental action (his doctrina in the primary sense of the term).Footnote ³⁶ Inasmuch as he is the Word and Wisdom of God, Christ restores us to the imago Dei both by defeating sin though his passion and resurrection (remedium) and by teaching us (exemplum) and empowering us (sacramentally) to live the life of grace inaugurated by the New Law.Footnote ³⁷

Aquinas believes that the purpose of creation is ‘that by visible things the invisible things of God should be made known’, and that ‘by the mystery of the incarnation are made known at once the goodness, the wisdom, the justice, and the power or might of God’.Footnote ³⁸ Creation and incarnation, accordingly, constitute doctrina, and Jesus's life, ministry, passion and resurrection likewise come under the heading of salvific teaching.Footnote ³⁹ More specifically, Aquinas argues that salvation can be seen in terms both of furtherance in good (promotio ad bonum) and withdrawal from evil (remotio a malo).Footnote ⁴⁰ Under the first heading, he lists four ways in which the incarnation operates as a doctrina which advances us towards the good ‘with regard to faith, which is made more certain by believing God himself who speaks’, ‘with regard to hope, which is thereby greatly strengthened’, ‘with regard to charity, which is thereby greatly enkindled’, and ‘with regard to well-doing, in which he set us an example’. To this he adds a fifth way in which the incarnation acts as a promotio ad bonum, this time, in effect, as a ‘remedy’ or ‘mystery’, ‘with regard to the full participation of the divinity, which is the true bliss of man and end of human life, which is bestowed upon us by Christ's humanity’. The second part of the quaestio, where Aquinas considers the incarnation as ordered towards remotio a malo, mirrors the structure of the first part, as Aquinas again proposes four ways in which the incarnation acts as a doctrina teaching us to withdraw from the devil and from sin, and concludes with a fifth way, a remedium, which has to do with the way in which Christ offers satisfaction for our sins and delivers us from captivity to the devil.

Moving on to the infancy narratives, Aquinas is always alert (for example, in his treatment of the place and time of the nativity, or the suitability of the epiphany) to the way in which events recounted in the biblical birth narratives (i) fulfill Old Testament prophecies, (ii) point to the mysteries of faith, and (iii) are in some sense a moment or phase in the unfolding of those mysteries. Aquinas makes particular use in these quaestiones of the idea of fittingness (conveniens), according to which the events and circumstances of Christ's life reflect the wisdom of the divine ordination and render credible and comprehensible the truth about who he is and what he does.Footnote ⁴¹ In explaining an event such as the circumcision (for example) he is careful to show how the doctrina points towards the remedium of the reality of Christ's human nature, the genuineness of his descent from Abraham, and the appropriateness of ‘his taking upon himself the burden of the Law that he might set others free’.Footnote ⁴² The event of the circumcision thus becomes both a doctrina which instructs us in this remedium concerning our redemption and justification, and, at the same time, represents an early stage in the unfolding of that remedium– a remedium which will culminate in the passion and which the faithful will appropriate through the sacraments.Footnote ⁴³

Writing about Jesus's ‘manner of life’, Aquinas suggests that Christ came into the world for three reasons: ‘that he might publish the truth’ (John 18:37) and preach the gospel (Luke 4:42–43), ‘that he might free human beings from sin’ (1 Timothy 1:15), and that ‘through him we might have access to God’ (Romans 5:2).Footnote ⁴⁴ Above all, ‘Christ wished to make his godhead known through his human nature. And therefore, since it is proper to humans to do so, he associated with humans, at the same time manifesting his godhead to all, by preaching and working miracles, and by leading among humans a blameless and righteous life’.Footnote ⁴⁵ In the process he follows ‘that form of active life in which human beings, by preaching and teaching, delivers to others the fruits of their contemplation’,Footnote ⁴⁶ and lives out his vocation to preach – to ‘publish the truth’– in such a way that his doctrina both points towards and, at the same time, is an integral part of, that remedium in virtue of which he liberates human beings from sin and offers them access to God.Footnote ⁴⁷ Exactly the same pattern is repeated in the quaestiones on Christ's temptation, miracles and transfiguration, in which Christ's actions constitute instructio and doctrina concerning his person and his redemptive work, while simultaneously being intrinsic to the unfolding narrative of that redemption.Footnote ⁴⁸ In each of the mysteries of his life and ministry, then, ‘the excellence of Christ's doctrine, which cannot be expressed in writing’ consists primarily in actions which represent instructio and doctrina about salvation to those who witness (and read about) them, but which are also ordered towards (and part of) the remedium of our accessing that grace of the New Law which, for Aquinas, quite literally ‘flows’ out from the passion and through the sacraments.

Even when addressing the passion itself, Aquinas gives as much weight to the passion as doctrina as he does to the passion as remedium. Most modern discussions of Aquinas's soteriology focus on the discussion of how the passion effects our salvation by way of merit, satisfaction, sacrifice, redemption and efficient causality,Footnote ⁴⁹ but Aquinas also insists that, while human beings were delivered from sin by the passion of Christ, ‘many other things besides deliverance from sin concurred for man's salvation’.Footnote ⁵⁰ For example, it is due to the passion that ‘we know how much God loves us, and are thereby stirred to love him in return, in which lies the perfection of human salvation’. Likewise, when considering whether it was suitable for Christ to die, Aquinas presents his death both as remedium (he died ‘to satisfy for the whole human race, which was sentenced to die on account of sin’) and as doctrina (he died ‘in order to show the reality of the flesh assumed’; ‘in order to deliver us from fearing death’; ‘in order to set us the example of dying to sin spiritually’; ‘in order to instill into us the hope of rising from the dead’).Footnote ⁵¹ Even the descent into hell is depicted as a remedium in virtue of which Christ delivers us from damnation (‘it was fitting for him to descend into hell in order to deliver us also from going down into hell’) and as a doctrina and instruction (‘that as he showed forth his power on earth by living and dying, so also he might manifested it in hell, by visiting it and enlightening it’).Footnote ⁵²

Finally, we should not be surprised that in discussing the fittingness of the resurrection Aquinas once again mirrors his account of the fittingness of the incarnation. Of the five reasons he gives for the necessity of Christ rising from the dead, the fifth corresponds to the category of remedium, in respect of which Aquinas writes that it was fitting for Jesus to rise ‘in order to complete the work of our salvation, because, just as for this reason did he endure evil things in dying that he might deliver us from evil, so was he glorified in rising again in order to advance us towards good things’.Footnote ⁵³ Here the argument centers round the idea that the resurrection of Jesus is a part of the narrative of salvation-history which culminates in the writing of the New Law (that is, the grace of the Spirit) on human hearts – an idea which is taken up in a subsequent quaestio where Aquinas shows how the resurrection operates by way of both efficient and exemplary causality as the cause of our own resurrection and justification.Footnote ⁵⁴ The other four reasons come into the category of instructio: ‘for the commendation of divine justice’, ‘for our instruction in the faith’, ‘for the raising of our hope’, and ‘to set in order the lives of the faithful’. Aquinas follows a similar pattern when discussing the effects of the ascension.Footnote ⁵⁵

In his commentary on the Epistle to the Hebrews, Aquinas quotes Augustine to the effect that ‘the cross is not only a victim's scaffold, but also a master's chair’.Footnote ⁵⁶ Each of the mysteries of Christ's birth, infancy, ministry, and passion and resurrection flows towards (or out of) the mystery of the victim's scaffold, and is ordered towards making satisfaction for sin, delivering us from the power of evil, fulfilling the Old Law and bringing in the New Law, and setting up a mechanism (the sacraments) whereby human beings can gain access to the benefits of all of this. However, these mysteries are also the teaching of a ‘master of theology’ which orient our minds towards the remedia of redemption, disposing us to appropriate the fruit of Christ's atoning work and to receive the New Law – the grace of the Spirit – which the supremely excellent teacher writes on human hearts. Matthew Levering is correct to draw on the idea of Wisdom christology to explain the interconnection of these functions: ‘Aquinas shows how each aspect of Jesus' ministry has an intelligible place in God's plan for human salvation through the words and deeds of Christ Jesus, who fulfills the purposes of divine Wisdom for Israel, as these purposes have been revealed in Israel's Torah’.Footnote ⁵⁷

The orderly manner of Christ's teaching

The third reason given why Jesus should not have written a book is ‘that his doctrine might reach all in an orderly manner, himself teaching his disciples immediately, and they subsequently teaching others, by preaching and writing, whereas if he himself had written, his doctrine would have reached all immediately’. The idea that Christ's doctrina should be preached in an ‘orderly manner’ is an important one for Aquinas, and can be viewed from three distinct but interconnected perspectives.

The first of these is salvation-historical. During the course of his discussion of the Old Law, Aquinas argues that (i) the Old Law was to lead humans to eternal happiness, and so brought nothing to perfection;Footnote ⁵⁸ (ii) the Old Law was given to the Jews because ‘although the salvation which was to come through Christ was prepared for all nations, it was necessary that Christ should be born of one people, which, for this reason, was privileged above other peoples’;Footnote ⁵⁹ (iii) at the time of Moses,‘it was fitting that this help should be bestowed on men in an orderly manner, so that they might be led from imperfection to perfection; wherefore it was becoming that the Old Law should be given between the law of nature and the law of grace’.Footnote ⁶⁰ According to Aquinas, the history of salvation – of human perfection – demands an orderly progression which culminates in the giving of the New Law by Jesus.

This idea of an orderly temporal progression is especially prominent in Aquinas's discussions of the Epiphany, where he argues that ‘it belongs to the order of divine wisdom that God's gifts and the secrets of his wisdom are not bestowed on all equally, but to some immediately, through whom they are made known to others’.Footnote ⁶¹ A similar point is made regarding the resurrection appearances: ‘his resurrection was not manifested to everyone, but to some, by whose testimony it could be brought to the knowledge of others’.Footnote ⁶² The divine ordinatio has determined that the preaching of the gospel should unfold in due sequence and through his chosen instruments – an idea which Aquinas elaborates with greater salvation-historical precision during his discussion of Christ's doctrine. Here he argues that ‘it was fitting that Christ's preaching, whether through himself or through his apostles, should be directed at first to the Jews alone’,Footnote ⁶³ and that Christ preached first to the Jews ‘in order to show that by his coming the promises were fulfilled which had been made to the Jews of old, and not to the Gentiles’. He explains that ‘the right order demanded that the doctrine of Christ should be made known first to the Jews, who, by believing in and worshiping one God, were nearer to God, and that it should be transmitted through them to the Gentiles’, and offers a comparison with the way in which, ‘in the heavenly hierarchy, the divine enlightenment comes to the lower angels through the higher’.Footnote ⁶⁴ The conversion of the Gentiles will happen at the appropriate time, which is after the passion –‘it was through the triumph of the cross that Christ merited power and lordship over the Gentiles’. Jesus sends out his disciples to ‘teach all nations’ (Matthew 28:19), and Aquinas observes that ‘it is a sign, not of lesser, but of greater power to do something by means of others rather than by oneself. And thus the divine power of Christ was specially shown in this, that he bestowed on the teaching of his disciples such a power that they converted the Gentiles to Christ, although these had heard nothing of him’.Footnote ⁶⁵

The second aspect under which we can view the idea that Christ's doctrina should be preached in an ‘orderly manner’ is that of sacramental signification. Aquinas explains that ‘a sacrament is a sign that is both a reminder of the past, i.e. the passion of Christ; and an indication of that which is effected in us by Christ's passion, i.e. grace; and a prognostic, that is, a foretelling of future glory’.Footnote ⁶⁶ Sacramental signs consist in sensible things through which human beings can acquire knowledge of spiritual and intelligible things.Footnote ⁶⁷ These signs vary according to the successive phases of salvation-history.Footnote ⁶⁸ Sacraments were not necessary in the state of innocence because of ‘the rectitude of that state, in which the higher (parts of man) ruled the lower, and nowise depended on them’. At that time ‘just as the mind was subject to God, so were the lower powers of the soul subject to the mind, and the body to the soul’, and nothing corporeal was required to perfect soul and body in knowledge and grace.Footnote ⁶⁹ After sin, however, ‘no one can be made holy save through Christ’, with the result that ‘before Christ's coming there was need for some visible signs whereby man might testify to his faith in the future coming of a Saviour’.Footnote ⁷⁰ The sacraments of the New Law differ from those of the Old inasmuch as ‘sacraments are signs in protestation of the faith whereby man is justified; and signs should vary according as they signify the future, the past, or the present’.Footnote ⁷¹ Accordingly, ‘the sacraments of the New Law, that signify Christ in relation to the past, must needs differ from those of the Old Law, which foreshadowed the future’. The state of the New Law ‘is between the state of the Old Law, whose figures are fulfilled in the New, and the state of glory, in which all truth will be openly and perfectly revealed’, but for now ‘we need sensible signs in order to reach spiritual things: and this is the province of the sacraments’.Footnote ⁷² The sacraments, then, reflect the ‘orderly manner’ of Christ's doctrina in the sense that through them he signifies spiritual truths in a way that reflects the ‘order’ of salvation-history with its successive phases and evolving requirements.

The final aspect under which we need to look at the ‘orderly manner’ in which the traditio of Christ's doctrina is handed on is that of the mystical body. Basing himself on Romans 12 and 1 Corinthians 12, Aquinas presents the church as a ‘mystical body’ of which Christ is the head. Christ is head of the church, firstly, because ‘on account of his nearness to God his grace is the highest and first, though not in time, since all have received grace on account of his grace’; secondly, because ‘he had perfection as regards the fullness of all graces’; and, thirdly, because ‘he has the power of bestowing grace on all the members of the church’.Footnote ⁷³ Within the mystical body, the humanity of Christ possesses ‘the power of influence, inasmuch as it is united to the Word of God, to whom his body is united through the soul’, with the result that ‘the whole humanity of Christ, i.e. according to soul and body, influences all’,Footnote ⁷⁴ and Christ as head directs the mystical body in both an interior and exterior way.Footnote ⁷⁵ Significantly, the grace which flows through the mystical body is Christ's own habitual grace,Footnote ⁷⁶ which is in turn the indwelling of the Spirit in Christ's humanity, in virtue of which Christ possesses the gifts and gratuitous graces of the Spirit,Footnote ⁷⁷ which latter ‘are ordained for the manifestation of faith and spiritual doctrine’, and which ‘were most excellently in Christ, as in the first and chief teacher of the faith’.Footnote ⁷⁸ It is against this background of ideas that, in answering the first of the objections put forward as to why Jesus should have written a book, Aquinas quotes Augustine to the effect that ‘Christ is the head of all his disciples who are members of his body. Consequently, when they put into writing what he showed forth and said to them, by no means must we say that he wrote nothing, since his members put forth that which they knew under his dictation. For at his command they, being his hands, as it were, wrote whatever he wished us to read concerning his deeds and words’.Footnote ⁷⁹

The reference to Proverbs 9:3 which follows (Wisdom ‘has sent her maids to invite to the tower’) suggests that the ‘orderly manner’ of proclaiming doctrina through the mystical body is all part of Jesus's fulfillment of the functions of the Old Testament figure of Wisdom. Inasmuch as he is incarnate Wisdom, ‘to give grace or the Holy Spirit belongs to Christ as he is God, authoritatively; but instrumentally it belongs also to him as man, inasmuch as his humanity is the instrument of his godhead’.Footnote ⁸⁰ However, in so far as he is human, Christ gives the Holy Spirit authoritatively (per auctoritatem), and, as members of his mystical body, other saints are said to give the Holy Spirit ‘instrumentally’ (instrumentaliter) or ‘ministerially’ (ministerialiter). The writing of the New Law on hearts, accordingly, is a work of the divine Wisdom accomplished instrumentally, by his humanity, his mystical body, and his sacraments. For Aquinas traditio is a work of the ‘whole Christ’, and preaching of Christ's doctrina in an ‘orderly manner’ requires not only an ‘order’ from Jews to Gentiles and Old Law to New Law, and an ‘order’ from one kind of sacramental revelation to another, but also an ‘order’ from the influentia of the head to the traditio of the members.

Why Jesus didn't write a book

Aquinas proposes three principal reasons why Jesus should not have written a book – his excellence as a teacher, the excellence of his teaching, and the requirement that his teaching should be disseminated in an orderly manner. Underlying these three reasons is Aquinas's understanding of salvation-history, according to which the rôle of Jesus is, in fulfillment of Jeremiah 31:31–33, to write the New Law on human hearts. Jesus's doctrina consists primarily in the grace of the Spirit, which he inscribes on hearts by means of the sacraments, and through which he offers access to the virtus and influentia of his saving passion, and secondarily in those precepts which he teaches during in his earthly ministry as recounted in the gospels, and which he continues to preach through the sacraments which operate as efficient causes and as signs. These precepts include not only his verbal teachings, but also every action of his life on earth from nativity through to resurrection and ascension, for ‘Christ's action is our instruction’, and it operates at the level of both mystery (or remedium) and example (or doctrina). If Jesus had written a book, it would have been, in effect, an updated Old Law rather than an authentic New Law. The New Law is one which is by definition written on hearts. His words, and, more especially, his actions, dispose us to receive the New Law which consists in the grace of the Spirit, and are themselves an integral part of the New Law. However, since ‘the letter kills, but the spirit gives life’, these are not what the New Law is all about. If Jesus had written a book, it would not, according to Aquinas, have bestowed life, happiness, charity and the grace of the Spirit.