The Church has traditionally condemned homosexual activity as incompatible with Christian discipleship. Today there are those who reassert the traditional position and others who want to see it reversed. Among the latter the question is sometimes asked: "what about usury?"

So, what about it? There are many ways in which the question can be asked and answered. The following is a brief outline in (overlapping) categories, drawing on my theses on usury.

(1) The rejectionist paradigm: The Church has rejected the prohibition of usury in Scripture, so we can reject Scriptural guidance on sexual activity. Stated blandly like this, it sounds a bit like "we have killed the shopkeepers, therefore we are permitted to loot the shops." Without more being said, this is not a way of arguing a case but of asserting a presumed right to overrule Scripture.

(2) The protestant paradigm: The Church has been wrong on usury, so it may be wrong on homosexual activity. For a Protestant, to say that the Church gets things wrong, even in important matters, is stating the obvious (cf. Art. 29 of The Thirty-Nine Articles). As an aside, it deserves to be pointed out that it is possible to allow for a Christian to earn interest, without considering the declarations on usury made in the early church wrong.

These are the two general options. Both rely on the widely held view that the Church's position on usury has changed, a view which is not universally shared, especially among  Roman Catholic authors (e.g., G. L. Coulter).

An appeal to usury as an analogy is hardly necessary to state these two views. The question is whether the analogy works at the level of specific reasoning as well. (If you are looking for easy answers, you may want to stop reading here.)

(3) The argument from difference in the activity condemned. It may be argued that the church did not know about commercial loans and for this reason can only be said to have condemned interest on charitable loans. A new socio-economic context demands new policies. Those who appeal to the analogy with usury along such lines may want to argue that the biblical condemnations of homosexual acts only apply to the kind of relationships attested in antiquity and that committed (and egalitarian) life-long homosexual partnerships were unknown in antiquity. 

There may be validity in this analogy with regard to the attitudes of the early church to usury but the following is often overlooked or denied: (a) loans for business purposes are older than the Bible, (b) the church fathers show some awareness of business loans, (c) usury was actually often permitted in medieval times both by the Church and Christian rulers - it just was not permitted among Christians, (d) while Scholastic theologians went to great lengths in trying to define what precisely was forbidden and what was permissible, their attempts do not distinguish between charitable and commercial loans and this in spite of the fact that both were known at the time.

(4) The argument from better insight. It is true that the Scholastic theologians from 1050 onwards and particularly in the thirteenth to sixteenth centuries begun to conceptualize loans differently, although this did not lead to a more permissive attitude to interest on loans in principle. In some ways, the opposite can be observed. The idea that a fixed interest rate on non-productive loans without shared risk is intrinsically immoral may well have been developed at that time. Arguably, it owes more to (the rediscovery of) Aristotle than the Church Fathers. Our rejection of this argument from natural law, where it is an informed rejection, likely owes more to the Austrian school of economics than to Calvin or any other theologian (see thesis 10 on time preference). I believe that a good case can be made for saying that Aquinas conceptualised loans wrongly, but this has rather less to do with the original condemnation of usury and its later permission than is sometimes thought.

With regard to Scripture, the argument from better insight can take two different forms, either outright rejection of Scriptural teaching ("we know better now") or appeal to accommodation ("the teaching of Scripture was exactly right for its time but not for ours"). The former apparently requires us to reject traditional views about God communicating His authority through the Scriptures, as few would want to claim they know better than God. The latter might appeal to the development of a "homosexual identity" in modern times but this is not without problems from a historical point of view.

All this is to demonstrate that the issues involved in discussing usury and the history of its discussion are far from straightforward. It is therefore imperative that those who seek to appeal to our evaluation of usury as an analogy for a proposed change in evaluating homosexual activity first establish the common ground on usury. It is not helpful to presume that we all have the same perspective on either the issue of usury itself or the way the Church has in the past handled it.

Today there may be two different moves towards lessening the strictures on usury. There is the legal-casuistic way, in which the law is still upheld in principle but with numerous qualifications which at their best prevent abuse of the law and at their worst provide means for circumventing the law. 

Those who seek to follow this paradigm in the debate on homosexual activity would reinforce the teaching that extra-marital sex is incompatible with Christian discipleship but provide for a wider definition of marriage which includes same-sex partnerships in which case the key question is whether this can be done legitimately.

Then there is the not-beyond-what-is-written principle: the conscience of Christians is not to be bound by rules and regulations which have no foundation in Scripture. While the Church may of course develop rules and traditions for the purposes of good order, a Reformed Catholic will not want to condemn actions which are not, implicitly or explicitly, condemned in Scripture.

Those who seek to apply this in the debate on homosexual activity need to demonstrate that the Scriptures do not in fact condemn the particular expression of homosexuality for which they wish to make space. But there are two differences with regard to the Scriptural argument which have the potential to invalidate the analogy and which would therefore need to be addressed. First, the specific OT restrictions on usury are not repeated in the NT, while the OT perspective on homosexual practices appears to be reinforced in the NT. Secondly, there is an exception clause to the prohibition of usury in Deut. 23:20, on the basis of which it can be argued that usury is not intrinsically immoral, while there is no such exception clause in either Old or New Testament with regard to homosexual practices.

Can the threefold division of the Law help? Yes and no. It reminds us of the unchanging character of God, whose moral demands remain the same across the ages. It reminds us of the fact that the ordering of societies which seek to conform to God's will may differ, depending on specific place and time and role in history. But we must do more than merely attempt to divide the Law.

Note also the essay by Andrew Goddard on  Calvin, Usury and Evangelical Moral Theology.