This got me thinking about the question of moral agency and language. In fact, I've come to the conclusion that moral agency is inherently tied up with language.
Some might object that animals possess language, but not moral agency. This is to a certain extent true. But I think that communication and language are rather two different things. Animals have the former, but not the later. My cat, Eleanor Aquinas, can communicate with me (in fact as you might have noticed she follows this blog). She tells me that's she hungry by crying or that she missed me while I was a work (again by crying) or that she loves me by lying next to me while I'm reading or trying to sleep.
This isn't exactly what I mean by language though. Language is not mere communication, but rather a dialogical address. The basis of such dialogical address is both command and promise. That is something Eleanor can't really do.
Moral agency only works if we can understand a series of commandments that oblige us. This means being able to know right from wrong and also being able to pledge ourselves to be obedient to said commandments. Similarly, because moral agency means obedience it means recognition of authority and the ability to pledge our allegiance to that authority. It also means other people's ability to pledge themselves to us in form of a contract or promise.
This mutual pledge in the form of covenant or contact can take a very a very trivial form or a very significant one. For example, if I go to McDonald's, I expect them to bring me my cheese burger to me after I've pledge my money. There is a moral relationship here via contract. On a much more complex level, there is a series of moral contracts between husbands and wives, as well as rulers and ruled. In either case, language must exist in some form. Otherwise there is no ability of the parties to pledge themselves to one another or command one another regarding their mutual expectations for the relationship.
This has two implications for the doctrine of God. First, God is the most perfect moral agent because he has a Word (the Second Person of the Trinity) which is stands in absolute fidelity to his being, in that he is a precise representation of the Father. The Son is a direct copy of the Father's will and therefore, in him, God is stands in absolute fidelity to his own nature and command. Similarly, he is the very self of the Father and therefore the direct presence of the Father's own promise. In Christ, therefore, God is not only true to himself in perfect holiness, he is also true to us in the form of his fulfillment of his promises of redemption. The gospel is literal giving of the Father's very self to us in Word and sacrament for the forgiveness of sins.
The second implication is that all of our speaking as moral agents presupposes God's own speaking. To command, we must have God's own prior command, or our moral maxims are but arbitrary preferences and therefore possess no transcendental basis. Secondly, as Burke points out, all contracts presuppose a transcendental basis in the form of divine guarantee to enforce them. This is the reason why we still swear on a Bible. Scripture promises that those who do not fulfill their moral contracts will suffer in either this life or in the next. Again, this later presupposition is necessary because without it all contracts will only be arbitrarily enforced to to the extent that one party can coerce the other into doing so.