The final item on the list of five types of prescription is “directly effective commands.” These are still a species of divine prescription, a species of revealed will and not yet disposing will. But unlike the species we’ve considered so far, they do not need to have any language-using human recipient. God says, “Let there be light,” and there is light. It’s tempting to say it’s not a command at all, but that’s too fast. The importance of the Genesis account here is that we are told that God accomplished creation through speech, in Greek logos. For Christians this suggests the role of the Second Person of the Trinity in creation, and John 1:1-3 takes up this suggestion, with explicit reference back to the first chapter of Genesis.
The idea of effecting something directly by commanding it may seem strange. But it’s not unique to the original creation. When the Psalmist says (Psalm 85:8), “Let me hear what God the Lord will speak, for he will speak peace to his people, to his faithful,” he is imagining God saying “Shalom,” “Peace be to you,” as the Lord says, for example, to Gideon in Judges 6:23. When God pronounces peace on us, that is a directly effective command, and a work of the Holy Spirit.
Perhaps the sense in which creation by directly effective command is a “communicative act” is attenuated. It might be a communication either within the Trinity, or to angelic beings, or to potential (but not yet actual) human recipients, or perhaps the implication of the doctrine of creation by speech is just that the creation is in principle intelligible. In any case, there is still the significant distinction to be made that this last kind of command, unlike precept and prohibition, does not presuppose the existence of human recipients and does not imply sanction or punishment for failure to comply. It’s important to see that this category of prescription nonetheless places creation in the category of something commanded. The claim of Ch. 4 is that God’s commands that produce our obligations are themselves constrained by the human nature that God created, but that this does not take us outside God’s commands to something else constraining God. Rather, God creates by command and sustains creation by command, and then commands us with one of the other types of divine prescription in a way that is consistent with that creative command.
We can now collect together these results and say that a divine command that generates obligation is a prescription with which the person commanded is not permitted not to comply, and a prescription in which there is an internal reference, by the meaning of this kind of speech act, to the authority of the speaker, and to some kind of condemnation if the command is not carried out.
Image: By Chris Light - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=59628755