A Greco-Roman issue called separation of powers. The principle vs. the theory

Yparraguirre E.M.A. · Revista de Derecho Politico (2026) · DOI: 10.5944/rdp.125.2026.48175

Resumen

The current constitutional doctrine assumes that the separation of powers appeared in the works of Locke and Montesquieu; however, this research argues that it is a Greco-Roman product. The valuable Greek experience was not foreign to tyrannical governments, which is why their philosophers had to reflect on the best forms of government and found that good life and happiness were political concepts, as politics would be for them a deeply ethical matter and the guarantee of just systems would rest on virtue. Aristotle, apart from his famous distinction between good and perverted regimes, recommends a tripartite model, where one element deliberates, another administers, and another judges. In the Roman Republic, it was tested a model that placed power in the Senate, the Magistracies, and the Assemblies, where functions were distributed among all these institutions and none of them were commanded by a single individual, especially the magistracies, which had as natural characteristics collegiality and temporality to avoid the concentration of power and the abuses they had experienced with the monarchy. Polybius, Titus Livy, and Cicero attest to this. The Greco-Roman world recognized the principle of separation of powers as a logical precept that prevented the consequences of its abuse. Since the 17th century, pre-revolutionary thinkers began to spread proposals for the creation of a new regime to replace the absolutist state. In this environment of the new liberal state, an idea was developed that defined the existence of three powers, each with specific functions. The mere distribution of power had not been sufficient for the Greeks and Romans, who demanded virtue in the political regime and not just a formal decentralization of power. Now, apart from the distribution of organs that had already been tried in ancient times, a specific separation of functions was also required, where each organ was separately in charge of the executive, legislative, and judicial powers, but with collaborative relationships between them. Thus, the idea shifted from a rigorous separatism that aimed for a sharp independence between the branches to a healthy and necessary interdependence that would not hinder the separation of powers. According to our research, the problem is semantic and epistemic, as in Greco-Roman antiquity we were faced with the principle of separation of powers, which implies a separation of organs and functions, distributed across all its institutions. Since the 17th century, we have been faced with a theory of the separation of powers, which is based on the principle but advocates for a separation of organs and a specific separation of functions, where each power assumes its own faculties that can be shared with the other powers. Copyright (c) 2026 Eduardo Martín Acosta Yparraguirre. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Instituciones: Universidad San Ignacio de Loyola