Thus, on a crucial question which had vexed scholastics for centuries: whether private property is natural or conventional, i.e. merely the product of positive law, Luther was characteristically anti-intellectual. He was not interested in such questions; therefore they were trivial: ‘it is vain to mention these things; they cannot be acquired by thought,...’. As Dr Gary North has commented, ‘So much for 1500 years of debate’.2 All in all, Richard Tawney's assessment of Luther on these matters is perhaps not an overstatement;
Confronted with the complexities of foreign trade and financial organization, or with the subtleties of economic analysis, he [Luther] is like a savage introduced to a dynamo or a steam engine. He is too frightened and angry even to feel curiosity. Attempts to explain the mechanism merely enrage him; he can only repeat that there is a devil in it, and that good Christians will not meddle with the mystery of iniquity.3
The rest is confusion. Upholding the commandment prohibiting theft meant that Luther had to be, at least in some sense, an advocate of the rights of private property. But to Luther, ‘stealing’ meant not only what everyone defines to be theft, but also ‘taking advantage of others at market, warehouses, wine and beer cellars, workshops...’. In different writings, sometimes even within the same one, Luther was capable of denouncing a person who ‘makes use of the market in his own wilful way, proud and defiant, as though he had a good right to sell at as high a price as he chose, and none could interfere’, while also writing: ‘Anyone may sell what he has for the highest price he can get, so long as he cheats no one’, and then defining such cheating as simply using false weights and measures.
On the just price, Luther tends to revert to the minority medieval view that a just price is not the market price but a cost of production plus expenses and profit for labour and risk of the merchant. On usury in particular, Luther tended to revert to the drastic prohibition that the Catholic Church had long left behind. The census contract he would ban, as he would lucrum cessans; money was sterile; there should be no increase in price for time as against cash payments for goods, etc. All the old nonsense, which the scholastics had spent centuries burying or transforming, was back intact. It is certainly fitting that, as we have seen, one of Luther's great theological opponents in Germany was his former friend, Johann Eck, a Catholic theologian and friend of the great Fugger banking family, who was even ahead of his time in arguing in thoroughgoing fashion in favour of usury.
Yet, despite his opposition to usury, Luther advised the young ruler of Saxony not to abolish interest or to relieve debtors of the burden of paying it. Interest is, after all, a ‘common plague that all have taken upon themselves. We must put up with it, therefore, and hold debtors to it’.
Some of these contradictions can be reconciled in the light of Luther's deeply pessimistic view of man and therefore of human institutions. In the wicked secular world, he believed, we cannot expect people or institutions to act in accordance with the Christian gospel. Therefore, in contrast to the Catholic attempt through the art of casuistry to apply moral principles to social and political life, Luther tended to privatize Christian morality and to leave the secular world and its rulers to operate in a pragmatic and, in practice, an unchecked manner.