Main question: For Aquinas, what authority would the state have independently of

Main question: For Aquinas, what authority would the state have independently of the Church to regulate religion? Why?
Justification: Aquinas’ stance on this topic illuminates the historical basis of discussion about religious freedom and the demarcation lines between secular and ecclesiastical authority. How come?
Methodology: this paper will analyze primary sources from Aquinas, focusing on his works on political philosophy and religion.
Key consideration: the significance of Aquinas’ theory of natural law and how it applies to creating a just society.
Recognizing the expression ‘the public good’ and its relationship with religious ritual. The extent to which Aquinas’ assertion validates the limitations of ecclesiastical and civil authority.

The expected outcome: This essay suggests that Aquinas would bolster a view that dismisses a state that can set limits on religion. While the state does need to promote the public good, it should not be in charge of people’s beliefs or displays of faith, except when these directly oppose orderly society or the common good.
Extra Study: By introducing a point of contention against the idea that the state may implement regulations on religious freedom based on Aquinas’ theories, this essay is a starting point for further analysis of how Aquinas’ ideas may relate to today’s discussions of religious liberty and the rule of law.
What you will find is that, at least on a surface reading, the chapters from De regno seem to be in tension with the Summa and Sentences texts, as De regno seems to suggest that the state does have an independent role in promoting eternal salvation and thus regulating religion. In order to prove your thesis, you need to explain how the three sets of texts (ST, the Sentences commentary, and DR) can be reconciled.
The paper is also meant to be a research paper, and so you will need to engage with secondary literature on the topic. Fortunately, there is a lot of material on your research question that will be helpful in developing your argument. In particular, you should consult the following sources and engage with them in your paper:
I.T. Eschmann, “St. Thomas Aquinas on the Two Powers,” Mediaeval Studies 20 (1958): 177–205; Paul Sigmund, “Law and Politics,” in The Cambridge Companion to Aquinas, eds. Norman Kretzmann and Eleonore Stump (Cambridge: Cambridge University Press, 1993), 219. (These two scholars both argue essentially the opposite of your conclusion)
William McCormick, S.J., “‘A Unity of Order’: Aquinas on the End of Politics,” Nova et Vetera 21 (2023): 1019–1041; Leonard Boyle, O.P., “The De Regno and the Two Powers,” in Facing History: A Different Thomas Aquinas (Louvain-la-Neuve: Collège Cardinal Mercier, 2000), 1–12; Laurence Fitzgerald, O.P., “St. Thomas Aquinas and the Two Powers,” Angelicum 56 (1979): 515–556. (these scholars try to show the compatibility of the texts).