As for Calvin, he stated that he gathered his tripartite view of the law from the "ancients who adopted this division, though they were not unaware that the two latter classes [judicial and ceremonial laws] had to do with morals." Therefore, like Aquinas, Calvin admitted that the laws which he called ceremonial and judicial had to do with morals, even so he, like Aquinas, adopted, defined, and used different categories for them. Unlike Aquinas, who tried to justify his reasoning through logic and some Scriptural exegesis, Calvin seemed to have relied on the wisdom of the ancients. It is of interest to note that Calvin did not say that the ancients justified this tripartite division of the law with solid Biblical arguments, but only that they "did not give them the name of moral, because they might be changed and abrogated without affecting morals." It is almost as if he assumed that the motivation of the ancients was derived by a need to fit their purpose, instead of being derived by the clear teaching of Scripture. Since this abrogation pattern is clear in Aquinas, could it be that Calvin suggested that this tension between the Decalogue's not being changed and the changing work of Christ was the motivation for Aquinas' arguments trying to justify a tripartite law? Possibly, but we have no proof of it.
In Calvin's theology, the law ultimately was divided as follows:
The moral law, ... is the true and eternal rule of righteousness prescribed to the men of all nations and of all times, who would frame their life agreeably to the will of God. ... The ceremonial law of the Jews was a tutelage by which the Lord was pleased to exercise, as it were, the childhood of that people, until the fullness of the time should come when he was fully to manifest his wisdom to the world, and exhibit the reality of those things which were then adumbrated by figures (Gal. 3:24; 4:4). The judicial law, given them as a kind of polity, delivered certain forms of equity and justice, by which they might live together innocently and quietly. And as that exercise in ceremonies properly pertained to the doctrine of piety, inasmuch as it kept the Jewish Church in the worship and religion of God, yet was still distinguishable from piety itself, so the judicial form, though it looked only to the best method of preserving that charity which is enjoined by the eternal law of God, was still something distinct from the precept of love itself. Therefore, as ceremonies might be abrogated without at all interfering with piety, so, also, when these judicial arrangements are removed, the duties and precepts of charity can still remain perpetual."
Therefore the moral law found in the Decalogue is timeless, but the ceremonial law and the judicial law are not. In this description, Calvin quotes Gal 3:24 as a supporting Scripture for his treatment of the ceremonial law. This passage, which in the letter to the Galatians comes at the end of a section on the purpose of the law, states: "Therefore the law was our tutor to bring us to Christ, that we might be justified by faith" (Gal 3:24 NKJV). It is hard to envision that this passage, written to a predominantly gentile church, was referring only to the Jewish nation, as Calvin would have it seem. Also, the context of the passage does not seem to allow for a purely ceremonial understanding of "the law," but to a more holistic understanding of the law. Therefore it is hard to agree with Calvin's definition of the ceremonial law based on this passage. As a matter of fact, if this passage is read in light of verse 25, where Paul writes: "But after faith has come, we are no longer under a tutor" (Gal 3:25 NKJV), one could understand this section of Scripture as arguing for a view where we are no longer under a tutor for the "whole" law, and therefore one does not need to hold to a tripartite division of the law.
In the next post, I will look at some more modern uses of the tripartite law, and their justification, or lack there of, for using it. In the meantime, if you are better acquainted with Calvin and his writings, do you know of anywhere else where Calvin does a better job of defending the tripartite division of the law?
 Calvin Institutes 4.20.14.
 Ibid., 4.20.15 (emphasis mine).
 In all fairness, one must at least consider the possibility that Paul here could have been using the term "we" to refer to his Jewish heritage rather than to him and his audience. While this interpretation would be more in line with Calvin's thought, it does not seem to square with the general sense of the passage and the specific use of "all" in verse 22.