Many thanks to Dr. Clark for taking the time to respond to me. There are some very helpful clarifications there of what he was trying to accomplish in writing his book. I am still left with a few questions that I would like to lay out there.
1. I agree that there is very little substantive difference between Calvin’s duplex gratia and Olevian’s duplex beneficium. This is not all that surprising, since, as Dr. Clark notes in his book, Olevian was Calvin’s student.
2. What is Dr. Clark’s definition of “substantive interaction?” He makes the claim that Garcia did not substantively interact with Cornelis Venema’s thesis. At the very end of page 11, and going through page 14, Garcia at least interacts with Venema’s thesis. The question is: does this qualify as “substantive?” Added to these pages, the footnote on page 34 may be added, which clarifies for us the relationship of Venema’s thesis to Garcia’s thesis. Given the crowded nature of theses on Calvin, my impression was that Garcia gave as much time to Venema as to anyone else. Not even Lillback or Armstrong receive more attention than Venema. Garcia was generally favorable to Venema’s thesis, while allowing that further development of various aspects of Venema’s thesis was possible.
3. I do not think that my question concerning union with Christ, justification, and sanctification is anachronistic. I think it genuinely is something that Calvin was dealing with. And in saying this, my motivation is to ask what Calvin believed, not to try to find some antecedent for my favorite theologians. Instead, I am asking the question in this way: is Gaffin correctly understanding Calvin? Is Garcia correctly understanding Calvin?
4. I am not so sure that it is a good idea to separate historical inquiry from systematic theology. We can distinguish them. However, compartmentalization of the two is not healthy, in my mind. This is the field of my thesis, by the way. The separation of the two enterprizes is not something that the Reformers would have done. They dance happily among the various theological disciplines (which only we, in our post-Enlightenment state, have separated) with almost no awareness that they have crossed the boundaries of disciplines. They engaged in historical theology in order to prove their systematic theses. Their systematic theses were historically conditioned. Both were grounded in exegesis and used in polemics against Rome, the Anabaptists, the Lutherans, and later on, the Socinians. All of this had profound practical ramifications for the Christian life. Why is it a good thing to cordon off historical theology from systematic theology? I know that this is how historical theology is done today. But should it be done this way?
5. What places in Calvin support the claim that union is an a posteriori explanation of how one comes to faith in Christ? My original question was whether justification and sanctification can be considered temporally distinct in view of the simul in Calvin’s Romans commentary. I do not feel that this question has been answered.
6. I would agree that the structure and doctrine of justification itself in the Reformed world of the 16th and 17th centuries is precisely the same as the Lutherans. It is in this sense that we can speak of a pan-Protestant doctrine of justification. However, it seems to me that the relationship of justification to other doctrines (like covenant and union with Christ) is where there are differences between the Reformed and the Lutherans. Would Dr. Clark agree with this assessment?
7. Why did Calvin treat sanctification before justification?