Thomas Aquinas was a systematic thinker.  The intellectual atmosphere into which Thomas was thrust was one of turmoil.  Islamic writers in North Africa and Spain had discovered the works of Aristotle and Muslim thinkers like Avicenna and Averroes had been trying to work out how the great insights they found in Aristotle matched up with the teachings of Mohammed. Averroes had come up with the boldest and most popular solution. He claimed that there were two entirely different sorts of truth: philosophical truth and theological truth, and that the two could contradict one another.  This meant that you could accept as philosophical truth Aristotle’s belief that the world did not have a beginning and, at the same time, affirm as theological truth that God created the world out of nothing.  This also had the convenient result that you could get on with philosophical speculation without regard to your religious beliefs and because what you were thinking about was ‘only’ philosophical truth you could claim that whatever you said did not prevent you from being an orthodox believer.

In Thomas’s day, Averroism was the rising intellectual force in the University of Paris.  Thomas saw the great danger for Christian faith in its ideas – follow the path of Averroism and you would end up with faith without reason and reason without faith.  You might think that that is where we have ended up today in the modern world.

Thomas was determined to stand against Averroism. He set out in his works, the Summa contra Gentiles and the Summa Theologiae, to show that Christian faith was reasonable, and that far from faith and reason contradicting one another, Christian faith was the best way to think reasonably.

Thomas’s solution was not perfect, and it either opened the way or was misunderstood as opening the way for saying that you reason first and that what you believe must be compatible with what you have arrived at rationally, without faith. Nonetheless, Thomas’s intellectual work ought to be appreciated for what it is, a brave and conscientious effort to think Christianly at a serious level that most of us will never attain.

One of the reasons why Aquinas is not read today is that he wrote in a particular, structured style, which takes some getting used to.  Each of the articles of Summa Theologiae is focused on answering a specific question and goes through the following process: 

1. Step 1: Ask the question (the issue to be considered)
2. Step 2: State the antithesis and give the best arguments for it. The antithesis is the position on the question opposite to the one that Aquinas is out to prove. These are called the objections.
3. Step 3: State the thesis and give the best arguments for it.  The thesis is the position on the question that Aquinas is out to prove.
4. Step 4: Refute each of the arguments for the antithesis by a strong counter argument. These are called replies to the objections.

Aquinas and the Bible:

Aquinas is typically accused of being more interested in Aristotle and angels than in Jesus Christ, but Aquinas’ thought, like that of Calvin’s, finds its centre not in his systematic work but in his careful commentaries on the Bible.  Both before and during the composition of the Summa Theologiae, Aquinas was giving biblical commentaries as lectures. He wrote commentaries on the Gospels of Matthew and John, all the Pauline letters (including, in his view, Hebrews), the Psalms, Job, Isaiah, Jeremiah and Lamentations. 

The God of Aquinas:

Aquinas begins his Summa Theologiae by talking about the characteristics of the one God.  It is only after he has done this that he goes on to talk about God as Trinity.  This approach has led to accusations that Aquinas’s God is a philosophical construct, based more on Greek metaphysics than on the Bible.  Aquinas’s defenders argue that Aquinas talks about God as One before talking about God as triune because this is how God has revealed Himself: as One in the Old Testament and as triune in the New Testament. 

Aquinas wrote in 1265: “The Christian faith consists above all in the confession of the Holy Trinity, and it glories especially in the cross of our Lord Jesus Christ.”

Aquinas on Law

Aquinas divides law into four types:

1. eternal law, which is God’s providence (ST I-II.91.1).
2. natural law,
3. divine law, which is divided into the Old Law and the New Law, and
4. human law.

Commenting on these four types of law, Nicholas Sagovsky says: the eternal law is the thoughts of God, natural law is the reflection of God’s decrees in creation, divine law is the will of God revealed through Scripture, and human law is the laws which people enact, hopefully in accordance with what they can discern of the law of God.

1. The eternal law

The question which Aquinas is trying to answer in his Treatise on Law in the Summa Theologiae is how God can work through all things, despite human sinfulness, to achieve his purposes of showing human beings how to live and of bringing human beings back to Godself.  The eternal law is the means by which God does this.

Eternal law is the law “ordered by God for the governance of things foreknown by him’ (ST I-II, 91, 1 ad.1). It is therefore to be equated with God’s providence, provided this is understood in the broadest terms as the entirety of God’s good purposes for this world that He has created (ST I-II.91.1). God’s providence is the ordering of things to their end, to the purpose for which they were created. It therefore encompasses both God’s ‘conservation of things in the good and their motion toward the good.” (Torrell, Aquinas, II:235).  In Trinitarian terms, the providential purposes of the Father are worked out by the Son (ST I-II.93.1 ad.2; 93.4. resp., ad.2) and the Spirit (ScG IV, 20).

2. The natural law

As we saw in our Session on natural law, Aquinas argued that all people know something of the natural law because “God puts it into men’s minds to be known naturally” (ST I.II.90.4 ad.1).  For Aquinas, the primary role of the natural law is to point out to those who know nothing of Christ, what God requires of them.  The self-evidence of natural law does not establish that we do not need God in order to discern right and wrong, rather it establishes our guilt for failing to order our lives according to the revelation of right and wrong, and of Godself, which the triune God has given us through the world God has made.

3.1 The Old Law

For Aquinas, there are three fundamental problems with natural law.  First, our knowledge of the natural goods towards which it directs us is obscured by sin.  Second, our natural ability to pursue those natural goods which we do discern is impaired by sin (ST I-II.93.6; I.113.1 ad.1).  Third, these natural goods are not the end for which we are ultimately ordered.  In order to direct us towards the end of eternal happiness with God (what Aquinas calls ‘eternal beatitude’), it was therefore necessary for a divine law to be given (ST I-II.91.4). 

The Torah operates at three levels.  It contains a revelation of the moral precepts of the natural law.  It is given in the context of a covenant by which God wishes to restore human beings to communion with God.  Finally, it points towards God’s will to enter into closer communion than would have been naturally possible.  Nonetheless, for all that this is the role of the Torah, it remains, like any human law, concerned with exterior acts and is not “an inner law which guides and perfects the movements of the soul.”

For Aquinas, the moral precepts contained in the Old Law are binding for all, because they reiterate the natural law (ST I-II.98.5).  These moral precepts can be reduced to the Decalogue (ST I-II.100.3), which can itself be reduced to the Two Great Commandments identified by Jesus.  The Old Law is therefore ordered to and around the love of God and the love of neighbour.

The fundamental problem with the Old Law was, however, that the Jews were unable to keep it.  As it looks forward to Christ, the Mosaic Law demonstrates that sinful human beings are incapable of perfectly following even a God-given law, which is acknowledged to be righteous (ST I-II.91.5). 

3.2 The New Law

Christ is the giver of the New Law, which is the grace of the Holy Spirit who writes God’s law on our hearts.  The New Law is “[t]he law of the Holy Spirit [which] is superior to every human law” (ST I-II.96.5 ad.2).  Through the Holy Spirit, Christians not only know God’s law but also receive God’s help to try to obey it.

4. Human Law

Aquinas’s understanding of salvation relegates human law to no more than the antechamber of God’s purposes at best. For Aquinas human law is only concerned with enforcing those matters of morality which belong to justice, i.e. those which relate to right relations between persons (ST I-II.99.5 ad.1).  We might talk of ‘shallow justice’ in distinction from the deep justice, that is justice-righteousness, which is the virtue which the Holy Spirit nurtures in the Christian.

Human law is necessary because of the effects of the Fall on humans’ ability to discern and obey the natural law.  It is because of human beings’ ability to misunderstand the natural law, that human law is necessary to make it effective on the political level.  It is because human selfishness means that we fail to give to others what is due to them, that human rulers must direct us to the common good (ST I.105.4).  In addition, the general principles of the natural law need to be spelt out for particular communities, and specific rules need to be devised to take account of the geography, temperament, manner and customs of the particular society which has to be governed. The rules of positive law are, and should be “always relative to a very particular context” (Opderbeck, Law and Theology, p.116).

Aquinas argued that precisely because “human law is established for the collectivity of human beings, most of whom have imperfect virtue … human law does not prohibit every kind of vice, from which the virtuous abstain.  Rather, human law prohibits only the more serious kinds of vice, from which most persons can abstain, and especially those vices that inflict harm on others, without the prohibition of which human society could not be preserved” (ST I-II.96.2; II-II.69.2 ad.1; 77.1 ad.1). 

Human law is powerless to effect true virtue.  Unlike the natural law and the Mosaic law, human law is not directly fulfilled in Christ.  It is not of eternal value in the same way.  It is a temporal ordinance, ordered providentially by God, during the time of humanity’s rebellion against him.

In ST I-II.98.1, Aquinas draws the following contrasts:

                              Human Law                              

End:                     the temporal tranquillity of the state                                                                                            

Means:              direction of external actions                                                                                                                                

Perfection:     prohibition and punishment of sin                                                                                                                                                                                                                                                                                                              

                               Divine Law       

End:                    everlasting happiness

Means:             the grace of the Holy Ghost spread abroad in our hearts

Perfection:    charity

With regard to the first distinction, a distinction has to be drawn between the perfect peace of heaven and the imperfect peace, which is the best that can be hoped for in this world (ST II-II.29.2 ad.4). 

With regard to the second distinction, the scope of human law is inherently limited because “human beings can judge only sensibly perceptible external acts, not hidden internal movements” (ST I-II.91.4). Human law is therefore content with ‘shallow justice’ while questions of ‘deep justice’ are matters for God alone.

With regard to the third distinction, since true justice is a work of the indwelling Spirit, and this human law is powerless to effect, therefore the role of human law in prohibiting and controlling vice must be more fundamental than its role in promoting virtue.

“The truly just person will enact a fourfold obedience to the law: they will at one at the same time obey the natural law, written on the human heart; the ‘positive law’ of the land, inasmuch as it reflects the natural law; the divine law as it is written in the Scriptures, and the Eternal Law, which is the eternal will of God for the good of His creation.” (Sagovsky, Christian Tradition and the Practice of Justice, p.109-10).

Nonetheless, where Augustine stresses the coercive nature of positive law, accepts that it must be practical in what it permits and what it prohibits, but holds rulers accountable to God’s justice, Aquinas, by contrast, emphasises that good laws are “directed toward the proper end of reason: the ‘common good’” (Opderbeck, Law and Theology, p.95), thus granting positive law a more constructive role.