---
title: "Jurisprudence"
chunk: 3/8
source: "https://en.wikipedia.org/wiki/Jurisprudence"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:58:04.446884+00:00"
instance: "kb-cron"
---

Aristotle is often said to be the father of natural law. Like his philosophical forefathers Socrates and Plato, Aristotle posited the existence of natural justice or natural right (dikaion physikon, δικαίον φυσικόν, Latin ius naturale). His association with natural law stems largely from his interpretation by Thomas Aquinas. This was based on Aquinas' conflation of natural law and natural right, the latter of which Aristotle posits in Book V of the Nicomachean Ethics (Book IV of the Eudemian Ethics). Aquinas's influence was such that it affected several early translations of these passages, though more recent translations render them more literally.
Aristotle's theory of justice is bound up in his idea of the golden mean. Indeed, his treatment of what he calls "political justice" derives from his discussion of "the just" as a moral virtue derived as the mean between opposing vices, just like every other virtue he describes. The longest discussion of his theory of justice occurs in Nicomachean Ethics and begins by asking what sort of mean a just act is. He argues that the term "justice" actually refers to two different but related ideas: general justice and particular justice. When a person's actions toward others are completely virtuous in all matters, Aristotle calls them "just" in the sense of "general justice"; as such, this idea of justice is more or less coextensive with virtue. "Particular" or "partial justice", by contrast, is the part of "general justice" or the individual virtue that is concerned with treating others equitably.
Aristotle moves from this unqualified discussion of justice to a qualified view of political justice, by which he means something close to the subject of modern jurisprudence. Of political justice, Aristotle argues that it is partly derived from nature and partly a matter of convention. This can be taken as a statement that is similar to the views of modern natural law theorists. But it must also be remembered that Aristotle is describing a view of morality, not a system of law, and therefore his remarks as to nature are about the grounding of the morality enacted as law, not the laws themselves.
The best evidence of Aristotle's having thought there was a natural law comes from the Rhetoric, where Aristotle notes that, aside from the "particular" laws that each people has set up for itself, there is a "common" law that is according to nature. The context of this remark, however, suggests only that Aristotle thought that it could be rhetorically advantageous to appeal to such a law, especially when the "particular" law of one's own city was adverse to the case being made, not that there actually was such a law. Aristotle, moreover, considered certain candidates for a universally valid, natural law to be wrong. Aristotle's theoretical paternity of the natural law tradition is consequently disputed.

=== Thomas Aquinas ===

Thomas Aquinas is the foremost classical proponent of natural theology and the father of the Thomistic school of philosophy, which for a long time was the primary philosophical approach of the Roman Catholic Church. The work for which he is best known is the Summa Theologiae. One of the thirty-five Doctors of the Church, he is considered by many Catholics to be the Church's greatest theologian. Consequently, many institutions of learning have been named after him.
Aquinas distinguished four kinds of law: eternal, natural, divine, and human:

Eternal law refers to divine reason, known only to God. It is God's plan for the universe. Man needs this plan; without it, he would lack direction.
Natural law is the "participation" in the eternal law by rational human creatures, and is discovered by reason
Divine law is revealed in the scriptures and is God's positive law for humanity
Human law is supported by reason and enacted for the common good.
Natural law is based on "first principles":

... this is the first precept of the law, that good is to be done and promoted, and evil is to be avoided. All other precepts of the natural law are based on this ...
Aquinas counts the desires to live and to procreate among those basic (natural) human values on which all other human values are based.

=== School of Salamanca ===

Francisco de Vitoria was perhaps the first to develop a theory of ius gentium (law of nations), and thus is an important figure in the transition to modernity. He extrapolated his ideas of legitimate sovereign power to international affairs, concluding that such affairs ought to be determined by forms that respect the rights of all and that the common good of the world should take precedence over the good of any single state. This meant that relations between states ought to pass from being justified by force to being justified by law and justice. Some scholars have challenged the standard account of the origins of International law, which emphasises the seminal text De iure belli ac pacis by Hugo Grotius, and have argued for the importance of Vitoria and, later, Suárez as forerunners and, potentially, founders of the field. Others, such as Koskenniemi, have argued that none of these humanist and scholastic thinkers can be understood to have founded international law in the modern sense, instead placing its origins in the post-1870 period.
Francisco Suárez, regarded as among the greatest scholastics after Aquinas, subdivided the concept of ius gentium. Working with already well-formed categories, he carefully distinguished ius inter gentes from ius intra gentes. Ius inter gentes (which corresponds to modern international law) was something common to the majority of countries, although, being positive law, not natural law, it was not necessarily universal. On the other hand, ius intra gentes, or civil law, is specific to each nation.

=== Lon Fuller ===