An Explanation of the Paradigmatic Discontinuity between Classical and Modern Natural Law: According to Aquinas and Grotius

Document Type : Research Paper

Authors

1 PhD Candidate of Philosophy and Theology, Shahid Motahari University, Tehran, Iran

2 Professor, Department of Moral Philosophy, University of Qom, Qom, Iran.

3 Professor, Department of Islamic Law, Shahid Beheshti University, Tehran, Iran

Abstract

Providing a conceptual account of the paradigmatic relationship between the natural law theories of Aquinas and Grotius within the framework of comparative moral philosophy is contentious on two grounds. First, some thinkers claim that natural law constitutes only a subsidiary element within Aquinas’s moral philosophy; accordingly, a comparative inquiry at the level of two complete theories is deemed methodologically untenable. Second, others argue that both Grotius and Aquinas belong to the tradition of classical ethics, and that no meaningful paradigmatic distinction can therefore be drawn between them. The present study challenge both claims and undertakes a comparative analysis of the principal components of these two theories. It argues that the paradigmatic rupture between them can be analyzed from two standpoints: (1) Fundamental/Radical Rupture: according to which discontinuity appears only in two components, namely practical reason and obligation; and (2) Hypothetical Rupture: if our perspective is the totality of Aquinas’s conceptual system, then, in addition to the previous components, there is also a rupture between the two in naturalism and in the definition of natural law. However, if we limit our interpretation to one of the levels of explanation in Aquinas’s works, namely practical reason, then no rupture exists between them in the latter two components. Beyond establishing the discursive rupture between these two theories, the central paradigmatic conclusion is that the articulation of the components of such a rupture is perspective-dependent and Hypothetical. Therefore, limiting their difference to the two components of practical reason and obligation does not contradict their rupture across the four aforementioned components, since each claim is grounded in a distinct perspective —whether the entire conceptual system or merely one explanatory level.

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An Explanation of the Paradigmatic Discontinuity between Classical and Modern Natural Law: According to Aquinas and Grotius

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References

Anscombe, G. E. M. (1958). Modern moral philosophy. Philosophy, 33(124), 1–19. https://doi.org/10.1017/S0031819100037943
Aquinas, T. (2000). On law, morality, and politics (2nd ed.). (R. J. Regan, Trans.). Hackett Publishing.
Crisp, R. (2013). Homeric ethics. In R. Crisp (Ed.), The Oxford handbook of the history of ethics (pp. 1–21). Oxford University Press.
Darwall, S. (2023). Modern moral philosophy: From Grotius to Kant. Cambridge University Press.
Finnis, J. (2011). Natural law and natural rights (2nd ed.). Oxford University Press.
Geddert, J. S. (2017). Hugo Grotius and the modern theology of freedom: Transcending natural rights. Routledge.
Gill, C. (2013). Cynicism and Stoicism. In R. Crisp (Ed.), The Oxford handbook of the history of ethics (pp. 93–112). Oxford University Press.
Grotius, H. (2005). The rights of war and peace (J. Barbeyrac, Ed.; K. Haakonssen, General Ed.; J. Clarke, Trans.; Vols. 1–3). Liberty Fund.
Hume, D. (2007). A treatise of human nature. Oxford University Press.
Irwin, T. (2008). The development of ethics: A historical and critical study: Vol. 2. From Suarez to Rousseau. Oxford University Press.
Irwin, T. H. (2013). Nature, law and natural law. In R. Crisp (Ed.), The Oxford handbook of the history of ethics (pp. 206–229). Oxford University Press.
Keenan, J. F. (Ed.). (2016). The ethics of Aquinas: A new introduction. Georgetown University Press.
Kraut, R. (2022). Aristotle’s ethics. In E. N. Zalta & U. Nodelman (Eds.), The Stanford encyclopedia of philosophy (Fall 2022 Edition). https://plato.stanford.edu/archives/fall2022/entries/aristotle-ethics/
Lisska, A. J. (1996). Aquinas's theory of natural law: An analytic reconstruction. Clarendon Press; Oxford University Press.
McCluskey, C. (2013). Thomism. In R. Crisp (Ed.), The Oxford handbook of the history of ethics (pp. 193–215). Oxford University Press.
Miller, J. (2021). Hugo Grotius. In E. N. Zalta (Ed.), The Stanford encyclopedia of philosophy (Spring 2021 Edition). Retrieved from https://plato.stanford.edu/archives/spr2021/entries/grotius/
Murphy, M. (2025). The natural law tradition in ethics. In E. N. Zalta & U. Nodelman (Eds.), The Stanford Encyclopedia of Philosophy (Summer 2025 Edition). Retrieved from https://plato.stanford.edu/archives/sum2025/entries/natural-law-ethics/
Shafer-Landau, R. (2018). The fundamentals of ethics (4th ed.). Oxford University Press.
Strauss, L. (1965). Natural right and history. University of Chicago Press.
Tollefsen, C. (2004). Natural law and modern meta-ethics: A guided tour. In M. J. Cherry (Ed.), Natural law and the possibility of a global ethics (pp. 39–56). Kluwer Academic Publishers.
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Journal of Philosophical Investigations
Volume 20, Issue 55 - Serial Number 55
Articles
Issue 55, Summer 2026
July 2026
Pages 113-128

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