It is hard to imagine that any aspect of Martin Luther's ideas or life is understudied. There are countless biographies in many languages, specialized analyses of his ideas about various theological, political, and intellectual topics, and journals and book series devoted completely to him. The five-hundredth anniversary of his birth in 1983 saw academic conferences and church-sponsored lectures all over the world, and interest in his ideas and the Protestant Reformation that resulted in part from them shows no signs of abating.

It is also hard to imagine, given the last twenty-five years of women's history, that the ideas of a man who wrote so much about women and who was so clearly influential would not have been analyzed to death. Educated men's ideas about women are one of the easiest things to investigate when exploring the experience of women in any culture, as they are more likely to be recorded than women's own ideas. For someone who lived, as Luther did, after the invention of the printing press, they might also be published and so widely available, not simply found in a single private letter or archival record. The sixteenth century was a period when men – and a few women – argued often in print about the nature of women, whether they were good or bad, human or not human, whether they had reason or were governed by their passions.

During the sixteenth and seventeenth centuries between 100,000 and 200,000 people were officially tried, and between 50,000 and 100,000 executed for witchcraft in Europe. Of these, about 80–85 percent were women, though this percentage varied throughout Europe. Both Protestant and Catholic authorities tried and executed witches, with the Holy Roman Empire, Switzerland, and eastern France seeing the highest levels of persecution. The early modern upsurge in witch trials – often called the “Witch Craze” or the “Great Witch Hunt” – is an extremely complex phenomenon which has been the subject of a huge number of studies over the last thirty years; most of these emphasize the ways in which economic, social, political, legal, theological, and intellectual factors all played a role.

Luther did not write a systematic treatise on witchcraft, so his ideas emerge in discussions of Biblical references to witchcraft and in the table talk. These ideas did not break dramatically with those of late medieval Christian thinkers. Most historians of witchcraft note that during the late Middle Ages, Christian philosophers and theologians developed a new idea about the most important characteristics of a witch. Until that period in Europe, as in most cultures throughout the world, a witch was a person who used magical forces to do evil deeds (maleficia). One was a witch, therefore, because of what one did, causing injuries or harm to animals and people. This notion of witchcraft continued in Europe, but to it was added a demonological component.

In his formal treatises, Luther revealed the very significant extent to which he retained and transmitted the traditional view that women by their nature were inferior to men. Particularly Luther's several commentaries on the first three chapters of Genesis demonstrate not only the Reformer's opinion that through their participation in the Fall, women became subordinate to their husbands. Luther was convinced that from the moment of Creation, Eve was a lesser being than Adam. This was why, he explained, the devil first approached Eve; she was vulnerable to temptation. Compared to Adam, Eve had always been less rational and more emotional than Adam. Nevertheless, she was devoted to God and assisted Adam in carrying out the divine command that the pair and their progeny should subdue the earth and govern all other creatures. Before her seduction by Satan, she had had more leeway in her daily activities – could even be absent from Adam for a period in pursuit of her tasks. She was an excellent if a lesser being, like the moon in relation to Adam the sun; the moon, too, Luther said, was a most excellent body. This analogy, like that of woman as a house or a snail with her shell, is an ancient one and not original to either Luther or the Reformation.

Having succumbed to Satan, Eve's relation to her husband changed as part of the penalty imposed by God. Now she had to stay close to him and obey him in all things.

Luther's ideas about women are tied to his ideas about sexuality. In some writings, such as the sermons and lectures on Genesis and particularly his comments about Eve, women's sexual nature is at the core of their being. He criticizes women, both prostitutes and other young women, for enticing young men into sexual relationships, with language that is much harsher than that discussing men enticing women. In other works, however, he concentrates more on male sexual desire and sexual activities, with women entering in primarily as desired objects rather than acting subjects. He regards sexual desire as extremely powerful in both men and women, but muses from time to time that women's weakness might make it even more difficult for them to control their desires than this was for men.

In Luther's opinion, the power of lust makes the truly chaste life impossible for all but a handful of individuals. Thus one of his earliest treatises attacks the value of vows of celibacy, and argues that the best Christian life is not one which fruitlessly attempts ascetic celibacy, but one in which sexual activity is channeled into marriage. Marriage is not a sacrament – Luther was adamant that it conferred no special grace – but it is the ideal state for almost everyone. Therefore the restrictions on marriage which had developed in the Middle Ages should be done away with, and everyone should marry, the earlier after puberty the better.

This book has taken a long while to complete, and has accrued many debts. In particular, I mention Professor Antony Black and Dr P. J. Fitzpatrick who, as always, shared their scholarship with me without stint. I mention also the editorial staff of the Cambridge University Press, and above all Virginia Catmur, to whose amazing skills as a copy-editor this volume, like my edition of Augustine's De civitate Dei in the same series, owes so much. Finally, I thank my colleagues and students at the University of Durham for their unfailing support, encouragement and stimulation.

St Thomas Aquinas

St Thomas was born in 1225 into a wealthy and influential south-Italian family. Landulph, his father, was Count of Aquino; Theodora, his mother, Countess of Teano; the family was related to the Emperors Henry VI and Frederick II, and to the Kings of Aragon, France and Castile. He began his education in 1230 as an oblate at the Benedictine monastery of Monte Cassino, where his uncle, Landulph Sinibaldi, was Abbot. In 1238 he entered the Studium generale at Naples. In 1245, despite great opposition from his family, he became a member of the Dominican order and went to the University of Paris, where the German theologian Albertus Magnus introduced him to the study of Aristotle. In 1248 he followed Albertus to Cologne. Between 1252 and 1256, as part of his preparation for his licentia docendi, he compiled his Scripta super libros sententiarum, the treatise on the Sentences of Peter Lombard, which had become a standard part of medieval university education. He received his licence to teach in 1256. The next eighteen years were spent teaching and studying at Paris, Naples, Orvieto, Viterbo and Rome. His Summa contra gentiles – a manual for missionaries to the Moslems and Jews of Spain and north Africa – was completed at Orvieto in 1264. He began the Summa theologiae at Rome in 1266 and worked on it until forced by ill health to desist in 1273.

Summa theologiae IIaIIae 66: On theft and robbery

Here there are nine things to consider:

1. Whether it is natural for man to possess external things

2. Whether it is lawful for anyone to possess something as his own

3. Whether the nature of theft lies in taking someone else's property secretly

4. Whether theft and robbery are sins of different species

5. Whether all theft is sinful

6. Whether theft is a mortal sin

7. Whether it is lawful to steal by reason of necessity

8. Whether all robbery is a mortal sin

9. Whether theft is a more grievous sin than robbery

articulus 1: Whether it is natural for man to possess external things

It seems that it is not natural for man to possess external things.

obiectio 1: For no man should claim for himself that which belongs to God. But dominion over all creatures belongs to God, according to Psalm 24:1: ‘The earth is the Lord's’, etc. Therefore it is not natural for man to possess external things.

obiectio 2: Moreover, Basil, expounding the words of the rich man at Luke 12:18, ‘I will gather all my fruits and my goods’, says: ‘Tell me: Which things are yours? Whence did you call them forth when you brought them to life?’ But whatever a man possesses naturally he can properly call his. Therefore man does not naturally possess external goods.

obiectio 3: Moreover, according to Ambrose in the book De Trinitate, ‘ownership is a title of power’. But man has no power over external things, for he cannot bring about any change in their nature. Therefore the possession of external things is not natural to man.

Summa theologiae IIaIae 90: The essence of law

Here there are four things to consider:

1. Whether law is something belonging to reason

2. The end of law

3. Its cause

4. Its promulgation

articulus 1: Whether law is something belonging to reason

It seems that law is not something belonging to reason.

obiectio 1: For the Apostle says (Romans 7:23): ‘I see another law in my members’, etc. But nothing which belongs to reason is ‘in’ the members, for reason does not make use of any corporeal organ. Therefore law is not something belonging to reason.

obiectio 2: Moreover, there is nothing in reason but power, habit, and act. But law is not a power of reason; similarly, it is not some habit of reason, because the habits of reason are the intellectual virtues, which have been spoken of above; nor again is it an act of reason: if it were, law would cease when the activity of reason ceases; for example, when we are asleep. Therefore law is not something belonging to reason.

obiectio 3: Moreover, law moves those subject to it to act rightly. But, properly speaking, it is the function of will to move someone to act, as is shown by what has been said above. Therefore law belongs not to reason, but to will; and this is in accordance with what the Jurist says: ‘What pleases the prince has the force of law.’

sed contra: It is a function of law to command and prohibit. But to command pertains to reason, as noted above. Therefore law is something belonging to reason.

Summa theologiae IIaIIae 10: On relations with unbelievers

articulus 8: Whether unbelievers ought to be coerced into the faith

It seems that unbelievers ought by no means to be coerced into the faith.

obiectio 1: For it is said at Matthew 13:28f that the servants of the householder in whose field tares had been sown asked him: ‘Wilt thou then that we go and gather them up?’ And he replied: ‘Nay, lest while ye gather up the tares, ye root up also the wheat with them.’ Commenting on this, Chrysostom says: ‘The Lord speaks thus in order to prevent the slaying of men. For it is not right to slay heretics, because if you kill them you will necessarily destroy many holy persons also.’ For the same reason, therefore, it seems that unbelievers ought not to be coerced into the faith.

obiectio 2: Moreover, it is said in the Decretum: ‘Concerning the Jews, the holy synod prescribes that henceforth none are to be brought to believe by force.’ Nor, therefore, for the same reason, ought other unbelievers to be coerced into the faith.

obiectio 3: Moreover, Augustine says that although a man can do many things unwillingly, ‘he cannot believe unless he is willing’. But the will cannot be compelled. Therefore it seems that unbelievers ought not to be coerced into the faith.

obiectio 4: Moreover, it is said at Ezekiel 18:32, as though God were speaking: ‘I desire not the death of the sinner.’ But we ought to conform our will to the Divine will, as stated above. Therefore again we should not desire unbelievers to be slain.

Summa theologiae Ia 96: Concerning the dominion which belonged to man in the state of innocence

articulus 3: Whether men were equal in the state of innocence

It seems that all men were equal in the state of innocence.

obiectio 1: For Gregory says: ‘Where we do not sin, we are all equal.’ But in the state of innocence there was no sin. Therefore all were equal.

obiectio 2: Moreover, similarity and equality are the basis of mutual love, according to Ecclesiasticus 13:19: ‘Every beast loveth its like; so also every man him that is nearest to himself.’ Now in that state there was among men abundant love, which is the bond of peace. Therefore all were equal in the state of innocence.

obiectio 3: Moreover, when the cause ceases, the effect ceases also. But the inequality which now exists among men seems to arise, on the side of God, from the fact that He rewards some and punishes others; and, on the side of nature, from the fact that some are born weak and disadvantaged by some defect of nature, whereas others are strong and perfect. But this would not have been so in the primitive state.

sed contra: It is said at Romans 13:1 that the things which come from God are ordered. But order seems to consist especially in disparity; for Augustine says: ‘Order is the disposition of equal and unequal things in such a way as to give to each its proper place.’ Therefore in the primitive state, in which everything was entirely proper, there would have been found disparity.

Summa theologiae IIaIIae 57: On right

Here there are four things to consider:

1. Whether right is the object of justice

2. Whether right is suitably divided into natural and positive right

3. Whether the ius gentium is the same as natural right

4. Whether paternal right and dominative right should be regarded as distinct species of right

articulus 1: Whether right [ius] is the object of justice [iustitia]

It seems that right is not the object of justice.

obiectio 1: For the jurist Celsus says that ‘right is the art of the good and equal’. But an art is not the object of justice, because art is an intellectual virtue in itself. Therefore right is not the object of justice.

obiectio 2: Moreover, Isidore says in the book Etymologies that ‘Law is a species of right.’ But the Philosopher identifies ‘legislative wisdom’ as one of the parts of practical wisdom [prudentia]. Hence law is the object not of justice, but of practical wisdom. Therefore right is not the object of justice.

obiectio 3: Moreover, the chief purpose of justice is to make a man subject to God; for in the book De moribus ecclesiae Augustine says that ‘justice is love serving God alone, and hence governing rightly all things subject to man’. But right [ius] does not pertain to things Divine, but only to things human; for Isidore, in the book Etymologies, says that ‘fas is the Divine law, and ius the human law’. Therefore right is not the object of justice.